Thicker than Blood

Chapter 1

A Brother and A Sister

Summary: Akaguro Chiyuki could remember everything from her birth and the life before then. It also just so happened she was born into a world she had seen in anime. She knew her brother was already set on a path she couldn't stop him from. Yet she loved him anyway.

Disclaimer: My character is Chiyuki, there are some other OCs that will be found in the story but I do not own My Hero Academia. This is on for a reason. You know. Fan-fiction.

The park was busy on the weekend with families and children. The playground was filled with children of all ages and sizes but there was one little girl who stood out. Chiyuki was off to the side of the park, picking at flowers with unusually deft hands. Chiyuki was four years old going on twenty-four mentally, having fully intact memories of the life she had before this one. It made for an oddly precocious child, even as far as precocious children could go.

As for the flowers, Chiyuki wasn't really supposed to be picking them from the park. But she needed flowers and for whatever reason the prices for official flower shop flowers had skyrocketed. She was not paying those overpriced prices for a bundle of flowers she could just as easily get from the park! Besides, Chiyuki smiled to herself, no one would really think much of a child playing in the flowers.

With a bundle in her arms that Chiyuki thought looked rather nice considering all things, she hurried through the park. She ignored the children on the playground, not really caring that she wasn't among them playing. At the entrance to the park she waited patiently for her big brother. She stood still and quiet, eyes darting up and down the street until she found his tall figure in the crowd.

Chiyuki took off towards her brother. She ducked around the legs of any unfortunate passerby who got in her way. She collided into her brother, stuffing the flowers into him. He lifted her up almost immediately, fitting her on his shoulders so that now she towered over most people.

"Got'em, Nii-chan!" Chiyuki beamed.

Despite her brothers manly appearance now clashing with the flowers she was starting to push into his hair, he grinned and held tight, "Good job, Chi-chan! Ready to visit Okaa-san and Otou-san?"

"Yes!"

Her brother walked with his back straight while he carried her. She tried to braid his hair with the flowers but she couldn't quite get her four year old fingers to work as well as she wanted. They passed a man who was taller than them by almost two of her and she turned to look at him with her lips in an O. Chiyuki had two years to get used to the strange new world she lived in but in the two years she had been aware of quirks, she had yet to fully get used to them.

They say reincarnation takes a minimum of five hundred years and while Chiyuki was more in the belief that her soul had just gotten launched instantly into another universe, she could understand the five hundred years thing. She hadn't learned much of the history of the world yet, and she was relatively excited to learn in school, but she did have some ideas from the world building of the story she knew.

Some time ago, Chiyuki estimating more than a few generations, there was a baby who was born that shined light. Soon after people starting to do the unthinkable and a majority of the world soon gained superhuman abilities previously only seen in comic books and movies. The world then had to go through a phase of rebuilding itself due to the new powers that had come to be known as 'quirks'.

Chiyuki had a few theories about what had happened to bring her here but regardless, she would likely never know, nor need to know. She was content to just learn to accept that quirks were now a thing that everyone had. She wasn't sure of her quirk yet but as her brother and she arrived at the graveyard, Chiyuki was reminded of her brother. He walked them, slowly to the grave that held both of their parents.

The grave was a boring headstone with an engraving that felt very impersonal. Chiyuki and her brother, after the tragedy of what happened, were never really consulted about funeral arrangements or anything. So now they had just a cold stone with the words 'Akaguro Chiyu and Nozome. Loving parents' to visit every so often.

"Hey Okaa-san. Otou-san," her brother began, setting her down proudly in front of the grave so she could start to organize the flowers she picked, "We're here to visit again. It's been two years since... the incident. Chi-chan is getting big and her hair is starting to grow out. She has your pretty face, Okaa-san. Good thing she doesn't look like me or dad."

"Nii-chan handsome." Chiyuki interrupted, patting his leg comfortingly. Chiyuki thought her brother was handsome in a rugged, rough kind of way.

Her brother laughed, "Thanks Chi-chan. Ah, it has been a little tough recently money-wise. I don't think I can afford to send Chi-chan to school until elementary school starts. But don't worry, I've been trying to teach her how to read and write. She's really smart and picks up kana way faster than I probably ever did."

"Yes. Reading is fun!" Chiyuki affirmed. With some string she tried to tie around the flowers she arranged in a not too shabby bouquet but her brother's big hands came to help her when everything started to come undone.

Her brother ruffled her wild hair, "We're doing fine. So don't worry about us. Chi-chan is safe with me. I won't let any harm come to her. No one will hurt her."

"Nii-chan!" Chiyuki whined to change the subject, "Sounds sad."

He smiled bitterly and pushed back the hair that covered her mangled ear. Luckily what killed her parents had only left minor cosmetic damage on her.

The two laid the bouquet in front of the grave and Chiyuki mentally said a few things to her parents. They had been good parents before they died and Chiyuki appreciated them. Before long Chiyuki's hand was grasped by her brother and they started to leave.

She looked up at her brother with warm eyes. Who knew that Akaguro Chizome, who would be come to be known as the Hero Killer Stain, would be such a doting older brother?

Gripping his hand a little harder Chiyuki felt the fire in her veins as she thought about what the future would hold for her precious older brother.

.

The pair lived in a ratty studio apartment. It was in a bad neighborhood so Chizome rarely let Chiyuki outside by herself. It was hard for him, Chiyuki knew. He had work that he had to do to earn money and it was hard supporting a small child. He hated leaving her alone in their apartment but he was currently working nights so that he was home with her in the day.

One morning, Chizome began teaching her how to read. He had a handful of flashcards that he showed her that had hiragana on them. Chiyuki caught on quickly and Chizome was a little surprised.

"You're picking this up really fast, Chi-chan. Okay. Maybe katakana next?" Chizome muttered to himself, grabbing for the clean pieces of paper and starting to cut out squares. Chiyuki held the hiragana cards and put down the cards for "Chi" "Yu" and "Ki" while proudly announcing she knew how to spell her name.

With a grin rapidly taking over her brothers mouth he whispered, a little shocked, "Wow, so amazing, Chi-chan!"

Chiyuki basked in the praise and the next day her brother was relatively surprised she had retained a lot of the hiragana from the day before and even some of the katakana. In a few days Chiyuki was asking for kanji but her brother decided to make flashcards for vocabulary instead. He was pretty terrible at drawing. Chiyuki recalled Okaa-san had been a good artist, having used hand drawn flashcards to help her learn speaking vocabulary.

Chizome held up a card with a cat that looked like it had a broken leg, "This is a cat, Chi-chan! It's spelled with 'Ne' and 'Ko' okay?"

Chiyuki forgave her brother for his terrible drawing skills and she took it in stride.

.

Chizome tried his hardest to give Chiyuki the healthy meals she needed but once she started eating real food as opposed to the baby food packages he could buy from the store, things got a little trickier. He didn't really know how to cook and going out to eat was too expensive for them. He had spent most of their grocery money on instant meals for him and the baby food for Chiyuki. Now he actually had to learn how to manage meals.

The neighborhood grocery store was sketchy so they walked further to the nicer grocery store. It was well lit and clean while offering deals that Chizome jumped on. He let Chiyuki carry the basket when they went together and she thought it was a little difficult when she was only barely tall enough to carry it. But it seemed to be something other children liked to do and she figured he saw other kids demanding to carry the basket, so shouldn't she like it too?

Chizome wasn't the best cook, they had learned rather quickly. He was twenty-one and should have been having fun as a college student. Well, Chiyuki doubted her brother, when he was Stain, went out and had fun.

"Ne, Chi-chan, they have discount chicken. That's something different we can try. Teriyaki chicken is good, how hard can that be to make?" Chizome said, picking up a package and squinting at it.

Chiyuki made a face, "Check the recipe book, Nii-chan."

Chizome laughed, "Alright alright."

After a few mishaps, Chizome had started to gather recipes from various places. He asked neighbors for some, sometimes he wrote them down from magazines and books. He had a nice journal going but he wasn't very good at organizing so it took him a few minutes to flip through to see if he had anything for chicken. As they stood, a voice cleared their throat behind them.

"Oh, sorry. Excuse me." Chizome, a little gruffly apologized, eyes still on his book as he gently led Chiyuki out of the way.

The woman who had excused herself shook her head, "No no. It's alright. Your little sister is very cute, by the way."

Chizome grinned, "Yes, she is!" He was a proud big brother.

Chiyuki eyed the woman who said that but she didn't look like anyone she knew.

The woman smiled down at her, "I have a son about your age. What is your name, little one?"

"Chiyuki." she answered a little cautiously.

Smiling the woman said, "A cute name for a cute little girl. Have a good day, you two!"

The woman grabbed what she needed and started to walk away. She seemed to have a second thought as she called over her shoulder, "Chicken pairs well with broccoli."

Chizome rubbed his head and seemed to take note of that. After the woman was gone he looked down at Chiyuki, "Well, I guess we find out if you like broccoli then."

"Does Nii-chan know how to cook broccoli?"

Chizome grinned, "Luckily, it's a vegetable so it can't be too hard."

They continued around the grocery store with Chizome taking the basket when it was too heavy for Chiyuki to carry. He let her wander the store and observe the different labels. When they waited to pay she pointed at the different words she could read, and calling out kana and asking what kanji were what.

"So smart, Chi-chan." Chizome praised as he asked how many yen the coins he was carrying made and she answered correctly. He had hardly taught her any math, but he had taught her enough to buy things with money.

Chiyuki felt a little bad that he would never know she was older than him.

.

Chiyuki learned to read at a pace that Chizome was both proud of and stunned by. By her fifth birthday she was already reading light novels.

"Ah, Chi-chan, I'm sorry I couldn't afford to send you to daycare or preschool. You could have learned a lot more than with me." Chizome apologized as they walked to the library for the day. It was on the way to his job which was convenient for both of them.

"It's okay, Nii-chan. The library has a lot of books." Chiyuki smiled. She was using this as a chance to try and improve her reading enough that she could learn more about the world history and quirks.

"Still. I wish I didn't have to leave you by yourself all day in the library." Chizome muttered rather crossly as they arrived. He walked her into the old building and Chiyuki led him to the section she was reading from today. She wasn't quite up to those books yet but she could still find entertainment and vocabulary in novels.

Chizome picked up one of the books and flipped through it, "Chi-chan, these are kind of boring."

"No they're not!" Chiyuki protested, "They're romance!"

Chizome sputtered, "Ah, on second thought I think you should go read in a different section. Why aren't you in the childrens section?"

"Too easy." Chiyuki dismissed, "I can't learn kanji in those books."

"Kanji already? I didn't learn that until elementary school..." Chizome looked at the book in his hands, "Ah, I'm glad you like learning so much Chi-chan. Okaa-san and Otou-san would be really proud."

Chiyuki looked down at the books and Chizome ruffled her hair, "I'm proud of you too. Really proud."

He left her alone for the day, promising to be back before the library closed. Chiyuki read through a light novel while wishing she could read something a little more advanced.

.

Chizome, for Chiyuki's fifth birthday, bought her cute hair ties and ribbons since her hair was getting a little longer. He also got a nice brush that had been on sale. Armed with these, he sat her down on the edge of his cot and moved the bathroom mirror so that she could look into the mirror as he tried to do her hair. He could do a high ponytail since he wore his hair in that. It was a little hard doing it on someone else, especially his small younger sister, but his first attempt didn't look too shabby.

"Ah, wait," Chizome said as he tried to pick out one of the small ties that attached by spinning little balls. He wrapped that around the band and grinned, "There we go, not too bad, right Chi-chan?"

"Nn!" Chiyuki agreed even though her hair was a little messy. Chizome likely thought the same thing as he tried to smooth her head down. She didn't think she looked too bad with a little white ponytail sticking up and green balls that matched her shirt.

Chizome sighed as he couldn't get her hair as neat as he'd wanted, "Well, I'll get better. This is practice for school."

Chiyuki was secretly very excited for school. But today was a different milestone for her.

"We're going to the park!" Chizome told her, very excited for her.

"Oh, to pick flowers for Otou-san and Okaa-san?" Chiyuki said.

Chizome shook his head, "No. You're going to play on the playground. I'm going to do adult things."

Chiyuki was a little confused on both ends. She had never played with other children before, nor had her brother mentioned adult things before.

"What kind of adult things?" Chiyuki asked, pouting when her brother laughed.

He pat her head, "Don't worry. It's just a lot of talking. I'll be keeping an eye on you so that you don't get hurt, too."

They walked to the nicer park shortly after that and Chizome pushed her towards the playground.

Chiyuki approached carefully, watching as children ran around wild. She took note of some of the quirks that made her a little nervous to be around. Some of these kids could accidentally kill her if she hit her wrong.

Deciding the sand box was the best bet, Chiyuki plopped herself down and ran her hands through the sand. She filtered it through and started to push the particles together into a hill. Trying to make it into a box, Chiyuki decided to make a castle. She was a little surprised when no kid came over to stomp through her creation. She was expecting some brat to come over and ruin it.

Starting on a second one, Chiyuki winced when someone plopped down next to her and pointed at her sand castle, loudly exclaiming, "Is that a house?"

"Kind of." Chiyuki said, "I guess."

The kid nodded their head. Chiyuki wasn't quite sure of their gender but they had orange hair and vibrant green eyes. Nothing about them was very obviously quirk related.

"I'mma make one too." decided the kid, trying to copy what Chiyuki was doing. The kid wasn't as dexterous as Chiyuki but their 'house' wasn't as ugly as it could have been. One of its walls was falling down but that was okay.

Chiyuki nodded slowly, "That's a nice house."

"Thanks!" the kid gave her a toothy grin. The kid wiggled their arms a bit and suddenly both sand castles were destroyed as the kids hand started to expand.

Chiyuki thought to herself, 'Yes, of course, as I decide this kid doesn't have a quirk that can harm me this happens.'

She thought she would be crushed but strong hands lifted her up and the kids mother came over to help. Chiyuki looked up and found her brother looking at the mother with an icy expression.

"I'm so sorry, Itsuka-chan is still trying to learn to control her quirk. I hope your daughter isn't hurt." the mother bowed.

Her brother's expression softened a bit, "Little sister. And no, she's not hurt. It's fine, some quirks are unpredictable."

Itsuka looked at Chiyuki and smiled again, "Sorry! Cool though, right? Big hands mean I can be a hero!"

Chizome looked at Itsuka for a moment and before he said anything, Chiyuki agreed, "Yes, your big hands are pretty cool."

"What's yours?" Itsuka asked.

Chiyuki blinked, "My what?"

"Quirk!" Itsuka beamed.

"Oh, I don't know. I haven't gotten mine yet." Chiyuki said, looking up at her brother a little nervously. He had never really mentioned quirks before to her.

Itsuka's mom looked a little concerned, "Pardon me if this is out of line but, your sister seems like she should have showed signs of a quirk by now. How old is she?"

"Five." Chizome said, "I'm sure she's just a late bloomer."

"Your parents should take her to see a doctor. Quirks almost always develop before four." the mother explained, a little awkwardly.

Alarmed, Chizome lifted Chiyuki onto his shoulders, "Ah, maybe that is a good idea. Sorry, we should be going now."

Chiyuki waved to Itsuka as the little girl waved wildly, saying, "Bye-bye, Shiro-chan!"

.

Chiyuki did not like sitting in front of the doctor as he scrutinized the x-ray of her leg. Her brother was in a chair next to hers, holding her hand tightly.

"Well," the doctor said, a little miffed, "Your sister is a little abnormal."

"How so?" Chizome almost demanded.

"Nothing serious but... her feet are different from each other. One foot has a bone that the other doesn't." the doctor explained, gesturing to the x-rays of both her feet.

In one extra her pinky toe had a little extra piece and in the other the bones looked a little more efficiently put together.

"Why does that matter?" Chizome asked.

The doctor gestured to Chiyuki, "I can't say if she'll develop a quirk. Generally the sign of some being quirkless is them having the extra bone. As Chiyuki-kun has this unusual case, she may develop a quirk or she may not. Just keep a watch on her. What were your parents quirks? And yours, for that matter?"

Chizome looked down, "Our mother had the quirk Snake, which meant she could extend her tongue great distances and she could bite on something and release poison from her teeth. Chi-chan's teeth are a little sharper than normal but it doesn't seem like she has Okaa-san's quirk. Our father had the quirk Blood Pact which allowed him to heal or hurt others by infecting them with his blood. He could heal his own wounds and anything he inflicted on himself passed over to whoever he made a pact with. My quirk is Bloodcurdle. If I ingest someones blood they are paralyzed for up to eight minutes. I do have a longer and more versatile tongue than normal, so I guess that came from Okaa-san."

The doctor was silent for a few minutes. He took down some notes and finally said, "It's possible she has a quirk that requires blood like you and your father. Her teeth suggest she may be developing a quirk. Chiyuki-kun, could you please open your mouth wide?"

Chiyuki did as asked and the doctor used a popsicle stick to poke around her mouth. When he was done he disposed of it in the trash and he said, "I think she'll be a special case, a late bloomer you could say. Perhaps when her baby teeth start to fall out and her adult teeth come she will start to show signs of something. Due to the nature of your quirk, I'm going to ask you don't try feeding her blood to see what happens. Let her develop naturally and if something doesn't happen by the time her adult teeth are in, I can do tests based on that idea."

Her brother let out a sigh that only Chiyuki heard.

"Alright, thank you very much, sensei." her brother bowed.

When they got home her brother snuggled into their kotatsu and she cozied up to his side. He leaned back against the bottom of the couch and he ran his hands through her hair.

"Sorry, Chi-chan. Nii-san isn't sure how to help you." Chizome murmured rather sadly.

"It'll be okay, Nii-san." Chiyuki promised.

.

Elementary school was a big change for Chiyuki. Her brother did her hair in two pigtails that day and he had been determined to make those pigtails perfect. She was on the younger side of the year, having a February birthday that put her at five years old only two months before school began. Her uniform was a cornflower blue and she wore a bright yellow hat to school. Her brother walked with her the first few days since he had put her in the nicer school that was a little further.

The first day, she hugged his legs as the teachers greeted them outside.

"Hello, who might this be?" a woman with lime green hair pulled into a bun asked, crouching down to be at Chiyuki's level.

Her brother let her answer and Chiyuki mumbled, "Akaguro Chiyuki."

"Well Chiyuki-chan, I'm your teacher. You can call me Konoko-sensei." the woman said softly.

Chiyuki gave a last cursory glance to her brother before walking, slowly, towards Konoko. He smiled like a proud parent as Chiyuki held the straps on her bag tightly and entered the school.

Konoko laughed, "She must think highly of you, big brother."

"Yeah well..." Chizome grumbled. Konoko laughed and told him Chiyuki would have a wonderful first day.

And it was a wonderful first day for Chiyuki.

She discovered the girl from her first visit to the park was in her class.

"Oh, Shiro-chan!" Itsuka greeted, "Do you remember me?"

"Yes, you're Itsuka-san." Chiyuki said slowly, "My name is Chiyuki, though, not Shiro."

"A nickname, then! You can call me a nickname too. We can be friends!" Itsuka decided and Chiyuki, a smile stretching across her lips, agreed.

"Nn, okay, Itsu-chan."

.

Chiyuki quickly discovered not having a quirk made her a bit of an outsider. Itsuka rarely enlarged her hands in school but sometimes they played games for quirk counseling time and Itsuka was allowed to use her hands then. She was good at the sports, especially baseball, since her hands could be so big. While Chiyuki didn't mind not having a quirk as the teachers didn't really bother her about it, it was a little disappointing when everyone in the class did something cool.

"Don'tcha worry," Itsuka told her one day during lunch, "You'll have the best quirk ever since you have to wait so long for it!"

"I sure hope so." Chiyuki agreed.

One of the boys listening sneered, "Red Eyes doesn't need a quirk, since her eyes are scary she can be a villain!"

Itsuka pushed her bento away and slammed a fist a little bigger than normal on the table, "Oi, what'd you say to my friend?"

"I said, Red Eyes don't need a quirk with her eyes!" the boy repeated, a little louder this time.

Konoko, who had a quirk that allowed her to sense the emotions in the room, hurried over to defuse the situation.

"Her eyes are pretty! She's so cute, I bet you just like her!" Itsuka returned, almost hollering.

The boy yelled, "Ew no way! She's ugly like her brother!"

Itsuka jumped when Chiyuki, who usually didn't care about the pettiness of the other children, slammed her fist on the table, "What'd you say about Nii-san?!"

"He's ugly like-" the boy hadn't even finished before Chiyuki was on the table, a fist full of his hair, and slamming his face into his bento.

Watching her friend with starry eyes, Itsuka blew a raspberry at the boys friends who were all very stunned.

Konoko grabbed Chiyuki by the back of her shirt and lifted her. The boy had already removed his face from his bento, tears already streaming down his face. He wasn't hurt, really, Chiyuki wasn't angry enough to actually hurt the kid. But the rice on his face probably felt humiliating. Konoko carried Chiyuki to the staff room where she dropped her in a chair and pinched her nose. She called for the principal and explained what had happened while Chiyuki watched with knowing eyes.

They called her guardian, her brother, who arrived about half an hour later still in his work clothes. That would have been fine but they had also called the boy's mother to come in. The two guardians and two children sat opposite of each other while Konoko and the principal sat as mediators.

"What happened to my poor Gensuto-kun?" the woman demanded. The boy, Gensuto, had yet to wipe the rice off his face.

Konoko raised a passive hand, "Gensuto-kun was insulting Chiyuki-chan until she responded by forcefully pushing his head into his bento."

The mother gasped but her eyes skimmed over Chiyuki and Chizome and she sniffed, "I expect a full apology, and an explanation as to why this child's parents couldn't even come to make that apology!"

Konoko went to answer but Chizome snorted. He leaned forward and said to the woman, eyes not leaving hers, "I'm sure if they were alive, our mother would be here. But as it is, if you want an apology, I don't think a headstone will make a very compelling one."

More insulted than anything else, the mother looked at the principal and Konoko as if they would say something in her favor.

The principal cleared his throat, "I think a mutual apology from both students is the best in this situation, Megane-san. Gensuto-kun did instigate."

Chiyuki looked straight as Gensuto and said, "I apologize for shoving your face into your bento, Megane-kun."

The room was quiet for a moment after her formal, and quick, apology.

Gensuto sniffed for a moment, looking a lot like his mother, before he mumbled, "I'm sorry too."

"What are you sorry for, kid?" Chizome question sternly before anyone else in the room could react to his apology. Gensuto's mother looked affonted, and went to open her mouth but her son spoke first.

"Telling Akaguro-chan she's ugly." Gensuto said, straightening his back a little bit.

Chiyuki looked up, "And?"

Gensuto looked away, muttering, "And, I guess your brother is kind of cool."

Chizome looked a bit miffed and Chiyuki nodded her head, "Please don't insult Nii-san again." But the way she said it, a bit coldly, suggested Gensuto would not be saying it again.

While Gensuto's mother didn't look very pacified, the principal had decided that since the children had made a compelling peace, the meeting was over and the punishments would be light. Both students were given extra homework as punishment, but they would be released early since the school day was nearly over.

As they were leaving, Chizome ruffled Chiyuki's head, "I'm glad you stuck up for yourself, Chi-chan. Try not to get in trouble when you do it, though."

Chiyuki nodded and both were visibly annoyed as they heard Gensuto's mother complaining into her cellphone as she pulled Gensuto by the hand out of the school, "-can you believe they made my sweet Gensuto-kun apologize to that trashy little girl? Honestly, she and her brother look like they came out of a dumpster! Not even the older brother seemed to know how to apologize. But what do you expect when dealing with orphans, ha!"

Chiyuki wanted to go after them, even Chizome was clenching his fists. But he also held them both back.

He knelt down, calming his breath as he huffed, "Sometimes, there will be people like that. You shouldn't use violence over something small and petty but I don't blame you. You're learning. I'm still learning too. We'll learn together, won't we, Chi-chan?"

"Nn! We will!" Chiyuki agreed, smiling wide. Somehow, she took that as a sign that her brother was becoming a better person too.

.

The first year of school was very easy for Chiyuki and her teacher was a little stumped about what to do with her. She soaked up math and reading like a sponge. Not to mention her interest in history meant she wasn't very satisfied by the dumb version of things they gave kids.

Chiyuki, as she walked home with Itsuka, complained, "I doubt they're telling us everything, Itsu-chan."

"Why would they lie, Shiro-chan? Being nice always helps, right?" Itsuka replied. Chiyuki almost replied, asking her how naive she was, when she realized that Itsuka wasn't naive. She was young. Chiyuki had nearly forgotten her friend was a child.

"Yeah. Being nice always helps." Chiyuki agreed.

But she wasn't settled on the matter by the time she got home. She tossed her hat and bag in their usual spot and she crawled onto her brother who was trying to nap on the couch.

He grunted and opened an eye as she started to complain, "Nii-san, they're teaching history wrong! They make everything seem so happy and nice but it's not!"

Chizome wrapped his arms around Chiyuki and she curled in next to him on the couch. He pat her head nicely, "What's the matter, Chi-chan? You're waking up your poor tired nii-san."

Chiyuki pouted, "Sorry, Nii-san. I'm just mad. Why are they teaching us things so dumb?"

"Ah, I think I know what you're trying to say." Chizome groaned as he pretended to roll onto Chiyuki. She giggled and Chizome spoke as she tried to get out from under him, "I know you're super smart, Chi-chan, but the other kids aren't. They aren't mature enough to understand that sometimes, good people do bad things."

"The world isn't black and white." Chiyuki said and Chizome groaned again, louder.

He rolled off her and looked at her, a serious look in his eyes, "Ah, you're growing up too fast Chi-chan. Stop being so smart and mature."

.

Chiyuki finished her first year with high grades and she turned six. Chizome was waiting for the day Chiyuki lost her first tooth but it had yet to come and he was a little impatient about the whole thing. He wanted to see if her quirk would develop or if they had to go bother the doctor some more.

"I'll lose a tooth eventually." Chiyuki said to him, wiggling a tooth with her finger, "Swee? Dis whuns woose!"

Chizome nodded, "Okay. Make sure you let me know if anything weird happens."

"Mmkay." Chiyuki agreed, taking the bento her brother had carefully made for her. His newest thing was realizing the mothers of her classmates made them cute bentos with characters and animals made of food. His cooking had improved a bit but his presentation was lacking as he had never considered this.

"I made you something special, today! Don't look until lunch though." Chizome said with an excited grin.

Chiyuki smiled, "I'm looking forward to it, Nii-san. I'll see you tonight." She gave him a hug, slipped on her shoes at the door, and called "I'm off!" as she started her walk to school. She hurried through her neighborhood and waited for Itsuka outside her house since it was close to the school. Itsuka came running out, carrying a bento wrapped in green cloth that matched her eyes.

"Ready for another good day?" Itsuka asked.

"Of course!" Chiyuki beamed.

The day did not go as planned, though.

At lunch Chiyuki opened her bento, pleased to see her brother had tried his hardest to make her bento cute. Itsuka leaned over, popping a hotdog cut to look like an octopus into her mouth, "Oooh."

"Nii-san made this special, this morning." Chiyuki said, smiling. There were two rice balls that looked like misshapen pandas and some baby carrots that were potentially intended to be rocket ships? The leftover chicken had cat faces drawn on in sauce.

Chiyuki lifted the first rice ball panda and nibbled on it happily as she observed the playground. She frowned though as she watched two larger boys drag a small one behind the bushes. Itsuka noticed too.

"We should tell sensei." Itsuka murmured.

"You do that." Chiyuki told her, handing her the bento her brother had carefully made her, "Keep this safe too. I'm gonna go try and stall while you get sensei."

"Okay! Roger that!" Itsuka said, hurrying towards the classroom with both bentos in hand. Chiyuki took a deep breath and ran towards the bushes. She crept through them slowly and peeked out to see Gensuto cower as he held his bento out to the two bullies. They took it happily, laughing at the anime character his mom had made the bento look like.

Chiyuki stepped out of the bush, "His mom made him that bento with love, so give it back!"

The two older boys looked at her slowly, then laughed.

"Hey, this pipsqueak thinks she can tell us what to do."

The boy closer to Gensuto put an arm around his shoulder and squeezed, "What'd we say about letting someone know? You wanna get the snot beat out of you again, kid?"

Chiyuki had miscalculated and thought the bullies were closer to their age. It was rude for two fifth years to gang up on a second year though.

Pointing at them, Chiyuki repeated, "Give him back his bento!"

"Or what? You'll make us?" the boy holding the bento laughed.

Chiyuki frowned. Her brother had never told her not to fight bullies, he just said use violence only when called for. Chiyuki decided these bullies deserved some kind of butt whooping before the teacher saved them.

She charged forward, kneeing into the balls of the boy holding the bento. He cried out, dropping to his knees. Chiyuki tugged the bento out of his hands easily as he grabbed at where she had hit. Chiyuki turned around, growling at the other boy.

Then his fist his her jaw and Chiyuki saw stars for a moment before she hit the ground, the bento cradled in her chest as she tried not to spill any of it.

"Akaguro-chan!" Gensuto yelped before covering his mouth, hoping no one would have heard him.

Chiyuki set the bento down next to her as she rolled onto her hands and knees to retch for a moment. She spit up a tooth and a splotch of blood.

"Ah, there's the tooth." Chiyuki muttered as her tongue felt the area her wiggly tooth had been, just that morning. It was a bottom front one, so no wonder it had gotten knocked out from that hit. She picked up her tooth and slipped it into her pocket.

The world tilted for a second and Chiyuki spit out a mouthful of blood this time. She looked at the puddle, thoroughly confused. A tooth shouldn't be causing this much blood, should it?

She turned to look at the boys and even the bullies looked very cowardly in that moment. Gensuto was grasping his hands together tightly, as if he was trying to hold himself together with that motion.

"I'm fineee." Chiyuki slurred, looking quizzically at herself when she heard the slur. She held up the bento she had gotten back, "Megane-sannn your bentooo."

The teacher arrived as Chiyuki lost a hold on herself and put the bento down harshly and collapsed right next to it.

.

Chizome was just getting into work after spending his lunch break outside preaching about his ideology on the revival of heroes. He had wanted to spend more time preaching but he had to work as hard as he could to support himself and Chiyuki. He figured if it weren't for Chiyuki he would have all the time in the world to spread his ideas. But he didn't resent her for taking his time. He loved his little sister very much.

"Akaguro-kun," his boss called from the office, "Your sister's school called."

"Ah, did she get in a fight again?" one of his coworkers asked.

The boss shook his head, "School says its a medical emergency. You should go pick her up."

Chizome was grabbing his things before the boss had even finished. As he was out the door the boss called, "Don't worry about today! It won't count against you!"

The school was twenty minutes walking distance away but he made it there in ten after sprinting the entire time. When he made it to the school he hurried to the infirmary where the nurse was standing with a wobbly Chiyuki.

"Gurgle." the nurse told her, "Good. Spit it into the sink."

Chiyuki spit something into the sink and turned to look at her brother. She gave him a wide smile and pointed to her mouth where one of her bottom front teeth was missing.

Chizome grabbed the door as he sighed in relief, muttering, "Medical emergency, huh."

The nurse gave him a strained smile, "Chiyuki-chan gave us a scare. The principal will probably tell you what happened but I'll keep Chiyuki-chan here while you go speak with him."

"Ah." Chizome nodded and he smiled at Chiyuki, "Don't worry, Chi-chan. I'll be right back and we can celebrate about you losing your first tooth."

He was directed to the principal's office where the man had him take a seat.

"Akaguro-san, thank you for coming. I'm sorry about the scare the call must have given you, Chiyuki-chan was unconscious and bleeding so we were thinking the worst. We didn't know it was a tooth until she woke up and told the nurse about her tooth." the principal apologized.

"No, I'm just glad she's alright." Chizome admitted, "Any false call is fine if it's about her health."

"Yes, I'm glad she's alright too. There is the matter of the incident that led to her tooth being knocked out." the princpial said, slowly.

Chizome narrowed his eyes, "Knocked out? It didn't just, fall out like teeth are supposed to?"

The principal sighed, "According to Chiyuki-chan's friend, they saw a classmate getting dragged away by two older students. Chiyuki-chan was supposed to distract the students while her friend retrieved a teacher but the students upset her and she hit one of the boys. The other student hit her, and being older he hit her rather hard. She looked like she was coughing up blood and gave the students such a scare, I doubt the two will hit anyone again for a long time. The nurse suspects she blacked out from the sudden unexpected injury, the tooth, and seeing so much blood."

Chizome nodded as he took in the story. Then he said, "Will there be any kinds of punishment?"

"The boys will be dealt with sternly, as they were bullying multiple students. Chiyuki-chan will be asked to write lines but for the most part, she's being regarded as a hero by the other students." the principal explained.

Satisfied, Chizome stood, "Can I take Chi-chan home?"

"Of course."

.

Chizome carried Chiyuki home, listening attentively as she retold the story of everything that had happened.

"-And then, they made fun of his bento. And I was so angry because even though Megane-san's mom is mean, she probably put a lot of love into that bento. Then those boys were going to eat it! I was so mad, but I was supposed to distract so I started by talking. But they just made me angrier, and I thought that I'd give them what they deserved. Since they pick on everyone and hurt everyone, I thought I should give them a taste of their own medicine!" Chiyuki explained energetically, swinging her legs as she munched on her bento that Itsuka had returned to her, unharmed.

"And did you?" Chizome asked, a little proud his sister had stood up for a boy who she had previously had an issue with. She was on the right track to knowing how to be a hero, he thought.

Chiyuki swallowed the last of the panda rice balls, "Well, one of them. I kneed him in the boy bits. Then-"

Her brother burst out laughing and Chiyuki paused. She pulled on his ponytail, "What, what? What's so funny?"

Apparently his laughter had brought a tear to his eye because he wiped his eyes with his sleeve, "The way you put that, 'boy bits', is a funny way to say that."

"Well, I think it's a good way to put it." Chiyuki defended.

"No, it is a good way to put it. Keep going, then." Chizome said, still snorting as he thought about his sister charging forward and nailing a bigger kid in his 'boy bits' as she put it.

Chiyuki continued, "Anyway, I went to turn around and be like, 'Look, I got your bento!' but then the other bully hit me. I kept the bento safe as I fell though and then I rolled over and spit out some blood and my tooth. Then some more blood. I wanted to give back the bento but I wasn't able to talk right and then I fell over."

Humming as he got the keys to their apartment ready, Chizome murmured, "I'm proud of you, even though you aren't supposed to use violence in school. I'm glad you stood up for someone weaker than you. A good hero sacrifices their own self to save someone else, but I'd rather keep my cute little Chi-chan in one piece. Okay? You know what I'm saying?"

"Yes, I understand, Nii-san." Chiyuki bowed her head and breathed into her brothers hair.

"Good, now, since you lost your first tooth, let's have some ice cream to celebrate!"

Chiyuki yelled in glee, she liked ice cream.

.

The next few days Chiyuki started to feel funny. At first she didn't notice as she felt more and more fatigued after doing things. But only a few days later Chiyuki was exhausted after a day of school and promptly fell into her shared bed with her brother and went to sleep. She only murmured things back at him when he tried to rouse her for food and for a bath.

The next morning, Chiyuki didn't have the strength to stand. She could barely sit up. When she expressed this to her brother, he took her seriously. The stressed look on her face assured him she wasn't just trying to get out of school like some kids did.

His heart beating fast he picked her up and hurried out the door with her still clutching her stuffed bunny, Usa-kun. He ran all the way to Hosu General Hospital where they admitted her and began running tests. She got a room to stay in with a few other beds occupied. Chizome drew the curtain closed around them as he held her hand, running his thumb over her surprisingly cold knuckles.

"Nii-san." Chiyuki said.

"It'll be okay Chi-chan. You're gonna be fine." Chizome whispered, kissing her hand.

"I'm scared, Nii-san." Chiyuki sniffled, tears forming in her eyes, "I'm so scared."

"It's going to be fine, Chi-chan. I promise. I will never let any harm come to you." Chizome promised her. It almost physically pained him as from her eyes dripped a few tears.

They caught pink in the light.

Chizome watched the tear dribble to her chin then disappear as she gulped. Another tear followed its path, this one a bit more pink. Then the next did the same. Then the next.

"Chi-chan, do you remember Otou-san crying?" Chizome asked quietly.

Chiyuki thought for a moment, "Yes. Only once."

"Good memory, Chi-chan. Do you remember why Otou-san never cried? It wasn't because he was supposed to be a big, scary daddy." Chizome explained patiently.

"Um." Chiyuki hummed for a couple seconds, "I think... did Otou-san have reddish pink tears?"

"I think you might be finding your quirk soon, Chi-chan." Chizome said, "Don't wipe your tears. They might scare you."

Chiyuki did anyway and found a streak of watered red on her trembling white hand.

.

Chizome didn't want to leave that night but the hospital kicked him out of the room. They offered him a blanket and pillow for the waiting room but, rather defeated, he said he would go home and get some of Chiyuki's books for him to read to her the next day. The hospital promised him the test results would be back soon and if anything happened they would send someone for him since they didn't own a phone.

Shuffling into the dark apartment, that night Chizome had a hard time sleeping. He was used to a warm, small body curled into his side, snoring very lightly. Now with the futon to himself it was lonely and cold. It was too quiet without her tiny breaths. He even missed how sometimes when she dreamed, she kicked her feet into him. Morning didn't come soon enough.

Chizome made a quick breakfast as he grabbed some of Chiyuki's favorite books the library had donated to her. He stopped by his workplace to explain Chiyuki was in the hospital and he would be at her side until she was better. His boss simply told him not to worry and to go. His coworkers had whispered words of prayer after Chizome explained what had happened and why he was so worried.

Arriving at the hospital he made a beeline for her room and one of the nurses stopped him before he entered. His heart almost stopped as the nurse told him, "She's been moved to a private room."

"Why?" Chizome whispered.

The nurse led him to the room where he found a doctor adjusting multiple bags and machines that were attached to his sister. Her eyes were closed and her skin was so pale she looked like she was seconds from death.

"Sensei, what did the tests say?" Chizome demanded as he put the books on a bedside table and grabbed the small hand that didn't have something attached to her finger.

The doctor stopped scribbling on his clipboard, "The tests were inconclusive. All night she kept worsening and we put her on as many IV drips as she can handle. For some reason her body isn't keeping and transporting nutrients. We're doing more blood work but so far it seems like her blood is thinning."

Chizome dropped his head so he could look at Chiyuki's face, "Will she wake up today?"

"Maybe. As far as tests can say, her body is working fine aside from what I just mentioned. Because her body isn't transporting things well, she's malnourished and has no energy." the doctor explained.

He left and Chizome grabbed his sisters hand. He didn't let go or leave until hours later when the hospital once again kicked him out. The entire time she hardly stirred.

.

The next day Chizome was back, but the room was empty.

The nurse in the station explained, "They needed to do an emergency blood transfusion."

Chizome thought his heart stopped, "What?!"

"Her blood was thinning so badly the rest of her body was starting to slow down. She should be back soon." the nurse said.

"Do you need any of my blood for her?" Chizome asked, looking at his arm as he wondered how much blood she needed and how much he could give.

The nurse looked up, scrutinizing him, "What blood type are you?"

"B" he answered, frowning when the nurse shook her head.

"Your sister is O, O negative in fact." the nurse said.

Chizome blinked slowly. Then he shook his head, "No, that can't be right."

"I'm sorry?" the nurse asked.

Chizome pulled out the paperwork from her last doctors visit. He held it to show the nurse and pointed to where it said 'Akaguro Chiyuki' and 'Blood Type: B Positive'.

The nurse grabbed the paper, skimming it with her face slowly turning pale, "This all can't be right. I'm going to bring this to the doctor immediately."

She rushed off and Chizome didn't even hesitate in following. A few nurses looked like they would challenge him when he followed her right into the surgical ward but his aura kept them back as he followed the nurse.

She stopped outside a set of doors and the pair waited in silence until the doors opened and a bed was wheeled out. Chiyuki, flushed with color and looking healthy again was pushed out with a dumbfounded doctor following. The nurse handed him the paper and the doctor skimmed it.

"I need a drink after this," the doctor said, rubbing his temple before looking at Chizome, "You. Your parents, bloodtypes."

"Uh, Okaa-san was B and Otou-san AB." Chizome answered after a second of thinking. The doctor's face darkened.

"Akaguro-san, whatever is happening to your sister is likely quirk related. I cannot fathom any other possibility." the doctor pulled at his hair in frustration, "Her blood type, before our eyes, was changing. She went in O negative and rotated through all the blood types multiple times."

"That's impossible!" the nurse gasped.

The doctor nodded, whispering, "I know."

Before they could continue, Chiyuki roused and opened her eyes. She took a moment to blink and get used to the light before she looked over at her brother and asked, "Nii-san?"

.

The hospital was in an uproar trying to figure out what was going on with Akaguro Chiyuki. As all the doctors spoke in passing, Chizome kept Chiyuki in her room. He read her books to her even though her strength was almost fully back now. The only time Chizome left the room was to get Chiyuki a drink whenever she asked.

The next day things were much of the same with Chiyuki still feeling fine. The hospital was almost ready to let her go when Chiyuki started to feeling an itch in her veins. She bit at the cup of water and her brother watched in concern as she drank a few cups of water and wasn't satisfied. Chizome mentioned this to the doctor and they watched her carefully. She started to ask for more food and she continued to chew on her cups and utensils.

The next day, things were worse. She was cold all day and her strength was turning to fatigue again. Tests showed her blood was once again starting to thin and cycle different blood types. The entire time Chiyuki drank and ate and drank and ate but the nutrients just weren't getting through. She was starting to weaken again.

Chizome was sitting with her that night, the hospital finally letting him stay after realizing this case wasn't going anywhere soon. He was letting Chiyuki play with his hand as he dozed off. He didn't even notice when Chiyuki had a sudden burst of energy where she could almost get out of bed.

He definitely noticed when sharp baby teeth were suddenly piercing the flesh in his hand.

Chizome jolted but didn't pull his hand back as his sister nibbled on his hand. He was used to pain from training and his sister teething on him wasn't new. She had teethed a bit on him when she was just a baby and their mother let him hold her. Although now she had teeth. Tiny sharp teeth.

"Nii-san," she whispered, retracting her red mouth from his hand, "I'm sorry but, I was just so thirsty... I'm still so thirsty but..."

With a weak smile Chizome joked, "It's fine, but I might start calling you a little vampire, Chi-chan. Since I can still move I guess you don't have my quirk."

He stilled and looked from his hand to his sister.

Chizome finally said, "Your doctor said not to feed you blood to find your quirk but, ironically, I think your quirk calls for it."

"Heh?" Chiyuki asked as Chizome offered her his bleeding hand.

She looked at it a bit strangely but when he made a licking gesture, she did so. She trusted her brother after all.

"Do you feel any stronger when you do this?" Chizome questioned.

Chiyuki nodded, "Nii-san, am I really a vampire?"

Chizome laughed, "Looks like you just need some blood to survive, like them."

Chiyuki was content to lick at her brother's wound, despite how weird she thought it was. She did feel stronger every time she swallowed. She didn't even mind the irony taste. Even her hunger started to go away.

After about half an hour of silence her brother suddenly said, "How am I going to explain this to your doctor, Chi-chan?"

.

A month later, Chiyuki was back in school. Despite all her time spent out, her teacher and principal figured she would catch up very quickly. She had been advanced anyway, this had just been a medical emergency break and they decided they could be lenient for that. Chizome had to give her updated health card to the nurse so he read over it as they walked to school.

Name: Akaguro Chiyuki

Age: Seven

Birthdate: February 4th

Eye Color: Red

Hair Color: White

Skin Tone: Caucasian, Tone 1

Blood Type: REDACTED

Allergies: None

Quirk: Blood Thirst

Quirk Details: Unknown

Special Needs: Requires blood supplemental drinks.

Guardian Notes: Will be sending with a white thermos with her name. This contains the blood. It's sixteen ounces of blood that she needs to drink. She's a responsible girl so just let her handle it.

As the nurse read the notes she looked at Chizome with both of her eyebrows raised.

He shrugged, "We're not sure what her quirk does yet, but we figured out how to stop it from killing her."

"Well, quirks always have their drawbacks." the nurse conceded. Although she did look at little awkward as she filed the health card.

"I suspect this one is going to be a double edged sword in every way possible." Chizome added, watching the nurse carefully.

She turned to look out the window where Chiyuki and Itsuka were being approached by Gensuto. Chizome followed her gaze with his eyes.

"She's a good girl. I hope this quirk doesn't change anything." the nurse said.

Scoffing, Chizome replied, "With a quirk like Blood Thirst, things will probably change in the future when we know what else it does."

The nurse hummed.

Outside, Chiyuki and Itsuka may have made a potential friend.

AN:

Hello! Welcome to my attempt at a Reincarnation OC in Boku no Hero! I haven't been in this archive before, but I'm really excited for this idea! Reincarnation fics in the Naruto archive are my weak spot. Most chapters probably won't be this long, but I'm very excited to write Stain's relationship with Chiyuki!

Normally, I put titles in the middle, but for whatever reason fanfiction was not letting me center the title and information at the top. Sorry!

Fun Fact: Originally, the story was going to start at her birth but I thought it would be better to give the parents in flashbacks and instead focus on what everyone cares about: Chizome and Chiyuki's relationship.

Please let me know what you think so far in the reviews!