It was one of those off nights. Well, least for Hiro it felt like an off night. He was looking forward to building stuff with Tadashi but had completely forgotten they were having guests over. Hiro wasn't shy in anyway, but he wasn't exactly social either. Tadashi was happy to talk with the adults and the other kids that were his age. Hiro… he'd rather just be building things. Making his own toys since the store toys never really pleased.

Though for a change he decided to be downstairs. He wouldn't talk to anyone but he wanted to be around Tadashi. Even if the boy was distracted by the two children he was talking to. Hiro didn't mind though. He was too focused on the toy he was modifying.

"Hm…" He hummed in thought as he looked at the robot he was holding. "Maybe rockets…?

"What you doing to the robot?"

He looked up to see a little girl crouching beside him, she had dark brown hair that was pulled back a bit and curious blue eyes.

"Is he broken?"

"No." Hiro shook his head quickly. "I'm making modi-" Hiro paused, trying to remember how it was pronounced. "Modifications!"

"Ooo… What are modifications?" The girl tilted her head. "I've heard the word before but don't know what it means."

"It means you add things to make something better or to fix it. This robot's not cool enough. So, I'm makin' it cooler." Hiro gave a little smirk. "Cause I'm an inventor!"

"Oh cool!" The girl squealed. "That's awesome!"

Hiro blushed a bit.

"T-Thanks. What's your name?" He tilted his head a bit.

"I'm Kathleen but you can call me Kat if you want. That's what my siblings call me most of the time."

"Kat… I like it. I'm Hiro!" Hiro pointed to where Tadashi was. "That's my big brother, Tadashi!"

"Oh so that's who Tadashi is. My brother Charlie and sister Alice talk with him all the time over the phone or are hanging out together. Never really talked to him myself though." Kathleen fumbled with her fingers. "He's older and stuff and I'm really shy."

"Really?" Hiro blinked. "Tadashi's nice though. He likes making friends with everyone… And can I tell ya a secret? I'm not shy but I don't really like talkin' to a lot of people."

"I get ya. I'm kind of the same way. I just never really know what to talk about." Kathleen giggled. "I don't know much yet but I can go on and on about cooking things… or books I've read. Even if they're little kids books as my siblings put it."

Hiro chuckled.

"I get ya. I like books too. I also like playing tricks on Dashi." He smirked. "Ever hear of a spider walk?"

"Sounds familiar." Kathleen tilted her head. "Is it fun?"

"Oh yeah! I like freaking out Tadashi with it. I can show ya." Hiro got a sneaky look in his eyes.

"Well… I'm bored… and if it can possibly freak out my siblings I'd like that." Kathleen smirked back.

Hiro grinned and put a finger to his lips before looking around to make sure Tadashi and Kathleen's siblings were faced away from them while they were talking. Hiro got on all fours, turning upright before moving quickly over to Tadashi, letting his head hang back, eyes looking wide.

"Onii-san."

Tadashi looked towards him, before jumping.

"GACK!"

The girl, Alice, squealed, leaping onto her brother's back.

"GAH! CHARLIE SAVE ME!"

Hiro cracked up, falling over as he laughed.

"GOT YA!"

"Haha… Very fun-"

Tadashi stopped short when Kathleen came up doing the same thing, though she was more focused on her siblings.

"Hiiiiii."

They both jumped, falling out of their chairs.

"GAH!"

"KAAAAT! THAT'S CREEPY!"

Hiro laughed harder.

Kathleen sat down on the floor, laughing.

"I was bored!"

Charlie looked to Tadashi.

"Your chibi corrupted our chibi." He deadpanned.

"... I'll be honest, I did not see that coming."

Kathleen giggled.

"Aren't you supposed to expect the unexpected?"

"...Touche'." Tadashi shook his head. "Evil chibis."

Hiro just smiled innocently.

"I love you too Nii-san."

"... GET 'EM!"

"Oh no-"

Kathleen and Hiro tried to run but it was too late. Both their respective siblings grabbed them, pulling them into headlocks, messing up their hair.

"BWAHAHAH!"

"ACK! CHARLIE! ALICE! NOT THE HAIR!"

"Too darn bad little sis!"

"Yeah. Kat!"

Hiro wiggled, laughing.

"DASHI!"

All the noise drew the attention of the adults. When they came in… they couldn't help but break down laughing.

"Oh goodness!" Kathleen's mother, Irene, laughed. "What the heck happened here!?"

"Hiro corrupted our sister!" Charlie smirked as he ruffled up Kathleen's hair more.

"That explains it." Aunt Cass laughed. "Naughty chibi!"

"Save meee! I'm being chibi huggled!"

"... Quick!" Irene got her camera instead, taking a picture.

Aunt Cass whipped out her phone, recording the event.

"Ah, this is just lovely."

"Hiro, COUNTERMEASURES!" Kathleen hugged her siblings, knocking them over. "HUG ATTACK!"

"Oof!"

"THIS IS THE MOST ADORABLE DEFEAT!"

Hiro grinned, doing the same to Tadashi as he fell over, the little boy cuddling close.

"Got ya!"

Tadashi smiled softly, hugging him close.

"Yes you do."

"So sweet." Aunt Cass smiled.

Almost like nothing is wrong in their world right now.

Kathleen huddled close to her siblings.

"And I got you two."

They hugged her close.

"Yep and we love you a lot."

"That's our baby sis."

Irene smiled softly.

"That's innocence right there."

"Something they should enjoy." Aunt Cass nodded. "After all, they're just kids."

"Yep… and I get the feeling they'll be close for a long time."

"You and me both Irene." Aunt Cass looked at the children, seeing them all laughing at each other. "You and me both."

Hiro and Kathleen looked to one another and smiled.

"Can we play more together?"

"Yeah! Auntie Cass, can Kat come over more?" Hiro gave a puppy eyed look.

"... HRK!"

Kathleen pouted as well.

"Please?"

"I don't think we can say no!" Irene put a hand over her chest. "Oh my goodness!"

"My heart can't take it!"

"Ooh I can operate on you guys!" Tadashi grinned.

"... Back off doctor chibi."

"So, yes?" Kathleen had a hopeful look. "I don't have a lot of friends after all."

"And neither do I!"

"...Yep. You two win."

"YAY!" Kathleen hugged Hiro. "You can show me all kinds of stuff!"

Hiro hugged Kathleen.

"Yeah! We can prank Tadashi and Charlie and Alice!"

The older siblings all groaned.

"We're doomed." Alice deadpanned.

"The most adorable beating ever."

"Deal with it." Hiro and Kathleen smirked.

Yep, Hiro's made himself a buddy.

Tadashi smiled.

I'm glad.

He only has one childhood after all.

A/N: Aileen: Hello everyone. I hope you have enjoyed reading this little short since this is the beginning of a new story collection for Big Hero 6! This time around we're focusing on the relationship of the Hamada Brothers and the Coleman Family. We'll be seeing stories about Kathleen and her siblings and their personal relationships with Hiro and Tadashi, be it friendship or in the case of Hiro and Kathleen, romance. However though, one special thing about this series that I'm gonna be trying out along with my co-writer, who is helping me write this whole thing. We're going to be writing many shorts and some will apply to certain timelines of different stories. Just depends on the short. I'll let Storm explain this one. Take it away my wing woman.

Storm: This series will be jumping from universe to universe within our different stories depending on our moods or just whatever feels right. Some will apply to almost all, some won't. Some will apply to stories like From the Ashes OR something like Immortal 7. Basically, we're just going to be playing with things here and not worrying about where it'll fit. Keep in mind though, some of these won't line up with Old Friends as that is specifically tailored to the Immortal 7 timeline, so please, do not point it out to us. We know already. Okay? All in all, this about the Hamadas and the Colemans and just... what happens when an extraordinary family meets an ordinary one. This first one with the exception of one AU (Mirror Image) applies across the board from Treatment Course to Digimon Hero 6. So, hope you enjoy.

Aileen: The main stories that these will link into are the following:

Treatment Course/Canon Big Hero 6, Immortal 7, From the Ashes/Digimon Hero 6, Mirror Image, and The Phoenix

The only ones that won't be featured are the following:

Still There, UnBroken, Jurassic Heroes and Kuro Tadashi

You're probably wondering why. Those four are alternate universe crossover. These stories are for the AUs that are in the canon Big Hero 6 world.

So, the beginning of each story we'll have labels that state which universe(s) the story applies to. Just a matter of context.

And that's it. Hope you enjoy this new collection.

- Aileen Rose and Storm Arashi