Obligatory Disclaimer: The "Inu Yasha" series and its characters are the property of Rumiko Takahashi, Sunrise, Shounen Sunday, Viz, and other corporate types. I am none of those entities. I'm just a silly fan writing silly stories because it's fun. Suing me would only be a waste of time and funds, so please don't. Any original characters that show up belong to themselves. Just ask them.

Author's Disclaimer: Thoughts and opinions expressed in this work of fiction do not necessarily reflect those of the author.

Overall Rating: M

I CHOOSE NOT TO WARN!
This story contains material that may be disturbing or outright triggering to some. Reader discretion advised.

Author's Note: I can't believe I'm finally getting up the guts to post this. :) The long-awaited sequel to "One Plus One". This is a direct sequel, so if you haven't read "One Plus One", a lot of things won't make sense, I'm afraid.

Before we begin, I have two very special people to thank. Without them, I don't think this would have seen the light of day.

First, I'd like to thank inufan625 for her unflagging support, calming me when I wibbled, and encouraging me through practically the entire year and a half that I was writing this. I would not have written this behemoth in such a short time if not for her. She's also an amazing writer in her own right, so if you haven't read her "Inu Yasha" fic, check them out!

I'd also like to thank the incomparable Youkai55 for helping me iron out the early chapters of this work so they are up to par with the later chapters, and constantly reminding me of my need to write. I'm a stubborn sort, and he puts up with me.. somehow. ^_- If you're at all a fan of Hanna Barbera's "SWAT Kats", read his fic! Go! Now! Not that I might be biased or anything...

Now please sit back, relax, and enjoy the ride.

Two Plus Two
By Misarae

Chapter One
Down and Dirty

"Whoo-hoo!"

Higurashi Sachiko raced down the stairs leading from the second floor where most of the classrooms were to the ground floor where the shoe lockers acted as a gateway between the world of academics and reality. Her long, dark brown, waist-length hair flew out behind her as she rounded the halfway point still at a run, using the handrail as a pivot. Even through the windows, she could see that it was a bright, sunny day outside, and it matched her mood perfectly.

She only wished she could safely take several steps at a time like her brother Naoki could.

Well, he wasn't her brother in the eyes of the law yet, but hopefully by the time they made it home, they would both know for sure. She'd been hoping and praying all day, knowing that this was the day her Mom and Papa were going down to the municipal office to find out if they could all finally be a legal family.

Sachiko could feel the slight weight of her Papa's fang bouncing against her skin from the cord made of braided hair that never left her throat, and her heart warmed. No matter what any lawyer or government official said, Naoki's biological father Inu Yasha was her Papa. So what if she was fully human and he was a hanyou? It was the love they all shared that mattered, and Sachiko knew they had that in spades.

Not to mention, this was the last day of school before summer vacation. Of course, she and Naoki had been "lucky" enough to draw cleaning duty on today of all days, but they had finished in record time. Naoki had urged her to go ahead while he put the cleaning supplies away, and she had hugged him in thanks, leaving him blushing and muttering behind her.

Nothing, but absolutely nothing, could ruin this day.

Sachiko practically bounced up to the small locker where her outside shoes were kept. She had just opened the locker and put her hand inside to grasp her white Mary Janes when the hairs on the back of her neck rose and the sound of a voice to her left made her freeze in her tracks.

"What're you smiling about?"

Sachiko took a deep breath and let it out slowly through her nose, trying not to panic. She'd know that voice anywhere, given how many times his and his cronies' laughter followed some poor kid being tortured. She and Naoki had been fortunate enough to escape his notice, or so she had thought.

She gave a slow count of three before continuing what she was doing, dropping her Mary Janes to the floor and lifting her feet to take off her school shoes without bending down.

"It's summer break. Why wouldn't I be smiling?" she asked, the brightness in her voice forced, but hopefully the bully wouldn't realize that.

"A bookworm like you? You'll shrivel up in the sunlight," came the nasty reply.

Sachiko rolled her eyes, then straightened her shoulders as she put one school shoe, then the other in her locker, keeping tabs on her opponent out of the corner of her eye. Something about her demeanor must have given him pause, as he simply watched her put them away in her locker before closing it with a satisfying bang. She turned to look her potential opponent straight in the eye before replying, "I bet you say that to all the girls."

His ice blue eyes would have been beautiful, if their expression wasn't so cruel. Oyama Katsuro had been terrorizing the younger students practically all year, and this would be his last chance before summer break. The sun coming in the windows picked out a few reddish highlights in his short, dark hair as he glared at the girl who dared talk back to him.

"No one talks to me like that," he said with a scowl.

Sachiko took a moment to step into her outside shoes, grateful that she didn't have to crouch down again to do so. "I just did," she said, picking up her backpack with an air of finality and moving to walk past him.

As soon as she had passed him, a deceptively strong hand closed over her shoulder, forcing her to stop. "Don't walk away from me!" Katsuro snarled.

"I don't like jerks, so I'm leaving." Sachiko tried to shrug him off.

Katsuro used his superior strength to whirl her around, giving her a nasty grin as soon as they were face to face. "You don't have a choice. I'm going to teach you a lesson in manners, pipsqueak!"

"Hey, let go of her!"

Sachiko froze at the sound of Naoki's voice. She had been hoping to shake off the older, stronger boy before Naoki made it downstairs. "Stay back, Naoki!" she cried, even though she knew beyond a shadow of a doubt that he wouldn't listen.

Katsuro casually turned his head toward the sound, keeping a steel grip on Sachiko. "Ah, looks like we have a party crasher."

Naoki slung his heavy backpack off his back, his fingers curling as he took up a defensive stance. "Fight me, instead! Or are you scared of a challenge?"

"Hey!" Sachiko protested, her brows knitting together as she frowned.

"Hah!" Katsuro sneered. "I can take you both on, no sweat!"

"We'll see about that!" Naoki cried as he charged toward them.

Sachiko bit back a scream as she felt Katsuro's grip on her shift, one arm going around her waist a split second before he bounded backward and up into the air, higher and faster than any human ever could. He landed on top of a row of lockers, dangling Sachiko over the edge.

Naoki fought down a wave of panic, the muscles in his legs tensing as he prepared to spring at a moment's notice. "If you're so tough, why're you using a girl as a shield?" he taunted.

Sachiko scowled. Had Naoki completely forgotten how they first met? Her fury overcame her shock, and she raked her nails down Katsuro's left arm, leaving four long, bloody scratches in their wake.

A very inhuman howl escaped Katsuro's throat as he was forced to drop her.

Naoki's eyes widened and he leapt to catch her. He got there just in time, bounding backward the moment he felt her weight in his arms, and the way her own arms circled around his neck. "What the heck were you thinking?" Naoki demanded.

"That I had to remind you I can fight just as well as you can, Naoki!" Sachiko replied, the fire in her eyes belying the desperate way she clung to him.

"You idiot!" he spat, then mentally winced, realizing how much like his Dad he sounded in that moment. Suddenly, a spike of youki caught his attention, bringing it back to Katsuro. He quickly realized they would probably destroy the locker room if they didn't take things outside. "He's a full youkai!" Naoki proclaimed, quickly bounding backward towards the exit.

"So?" Sachiko retorted.

"So? SO?!"

"Heh, wimpy little pup's running away," Katsuro jeered.

"Catch me if you can!" Naoki hollered back, turning fully away from their opponent and running as fast as he could.

Sachiko let go of his neck and struggled against his hold. "Naoki, put me down!" she demanded.

"Not a chance," Naoki replied.

"We can fight him together!"

Naoki could tell that Sachiko was furious with him, but he didn't need a battle on two fronts. "You get hurt, both Mom and Dad will kill me." He made it halfway across the school courtyard before he suddenly felt something solid connect with his legs, sending him crashing to the ground. He curled around Sachiko as best he could, trying to shield her from the fall.

Sachiko used the opportunity to wriggle out of his hold.

"Sachiko!"

Sachiko ducked as Katsuro tried to grab her.

Naoki launched himself at their assailant, bringing them both down to the ground.

Katsuro was older, taller, and more agile, but Naoki was determined. As long as Sachiko was kept safe, that was what mattered. Katsuro's technique was sloppy, Naoki dodging the vast majority of Katsuro's blows thanks to the training that came naturally from his years of "roughhousing" with his Dad in true inu youkai fashion. Naoki got in a good few slugs of his own, but they weren't powerful enough to stop an older, full youkai.

As they rolled around and around, battling for dominance, Sachiko looked around to try and find something, anything, she could use as a weapon. Then she spied a few large rocks nearby. She gathered them up, and as soon as the boys stopped moving for a split second, she took aim.

"Ow! What the..!" Katsuro trailed off as he ducked to avoid Sachiko's latest projectile, which otherwise would have hit him in the eye. "Knock it off!"

"Leave my brother alone, you jerk!" Sachiko cried.

"Brother?" Katsuro inhaled. "Hah! You hardly have any youkai blood at all!" he said to Naoki.

"I can still take you!" Naoki said through gritted teeth.

"Hah. You're going to wish you'd never been born by the time I'm done with you, mutt!"

"Right back at you."

Those four snarled words were the only warning Katsuro had before he was bodily lifted off of Naoki. Katsuro struggled, but whoever had him wrenched his arms behind his back, straining them painfully even as his feet hit the ground.

"Keh, you're just a wimpy little wolf cub. Why don't you pick on someone your own size?"

Naoki wanted to simply sprawl out on the ground in relief as Sachiko cried out, "Papa!"

Instead, Naoki slowly, warily got to his feet. He met his Dad's eyes, expecting a reprimand, but instead there was pride written all over his face.

"Well fought, pup," Inu Yasha praised.

Naoki blushed.

"Hey, what are you doing to my son?"

They all turned to see a muscular, dark-haired, blue-eyed man stalking toward them. Inu Yasha took up a defensive stance, while not letting up his grip on the boy.

"Making sure he doesn't attack imy pups again," Inu Yasha spat back. "Who're you?"

"What's it to you, dog turd?"

"Nothing. Just wanted to know what name to report to the school."

"The bully's name is Oyama Katsuro!" Sachiko said.

"Shut up, pipsqueak!"

The adult male wolf youkai came up to Inu Yasha, and Inu Yasha bristled. Then he nearly let Katsuro go in shock as the wolf youkai punched his son in the gut. Katsuro crumpled.

"Do you WANT humans to come after us again, you moron?" Katsuro's father demanded. "If you're gonna pick a fight, pick it with other youkai!"

"But Pops..."

"No buts." Katsuro's father turned to Sachiko. "How long's he been doing this?"

Sachiko straightened, finding extra courage in the fact that somehow it seemed Katsuro's father was on their side. "Since early in the school year. He's always picking on the youngest and weakest students."

"Law of survival: the strongest win!" Katsuro spat.

"I said, shut the hell up!" Katsuro's father cuffed him across the mouth, making Katsuro look up at him, stunned. "What have they been teaching you here, or are you just acting up because your mother and I aren't here to put the hurt on you?"

Katsuro looked away, shamefaced.

"What happened to your arm?" Kouga asked, his nose picking up and tracing the slightly bloody scratches on Katsuro's currently hidden forearm.

Katsuro's rage came back. "SHE did it!" he spat.

"He grabbed me. Jerk," Sachiko retorted.

His curiosity piqued by the other scents surrounding them, Kouga took a deep breath in Sachiko's direction, before looking back at Inu Yasha. "She's not yours. She's human."

"Sachiko, show him your necklace," Inu Yasha said.

Sachiko drew out the charm made of Inu Yasha's fang, and his and Naoki's hair.

Katsuro's father's eyes snapped from the necklace, then back to Inu Yasha, finally catching sight of Inu Yasha's Intention beads.

"Crap," Katsuro's father muttered.

"Yeah, you're lucky Sachiko didn't purify him," Inu Yasha said, certain that the wolf youkai had no way of telling whether Sachiko had fully come into her powers yet or not.

Katsuro's father's lips drew into a tight line for a moment before he spoke. "He won't be bothering you, or anyone else at this school, again."

"But POPS!"

"Quiet!" Katsuro's father snarled, before practically ripping him out of Inu Yasha's grip. "He'll be dealt with. Properly."

Inu Yasha nodded. "Thanks."

"I'm Kouga, by the way."

"Inu Yasha."

"Come on, cub," Kouga said to Katsuro. "We're going to have a very long, very painful talk."

Inu Yasha, Naoki, and Sachiko watched as Kouga frog-marched his son out of the school courtyard.

"He's not really going to hurt him, is he?" Sachiko asked.

Inu Yasha sighed, trying to work out the tension in his muscles. "Not badly, for a youkai. Wolves and wolf youkai are practically extinct here in Japan. They usually have a little more self-preservation than that cub. You said he's been pulling that crap all year?"

Sachiko nodded, and Naoki said, "He's the biggest bully in school. Sachiko and I've been lucky until today. He tends to pick on weaker, smaller kids."

"Most of the human bullies leave us alone now, because we've kicked their butts. It's just bigger, stronger ones like Katsuro that we've tried to avoid," Sachiko added.

Naoki frowned, trying to shake off the last remnants of adrenaline still coursing through his system. "Then he cornered Sachiko at the shoe lockers today."

"You two fought well," Inu Yasha said. Then he realized he could still smell the wolf cub's presence, and traced it to the blood under Sachiko's fingernails. "We need to get home, but we should wash Sachiko's hands first. No sense worrying your Mom."

Sachiko looked at her hands and grimaced. "Ew."

Inu Yasha ruffled her hair. "Fighting's messy," he said. "Come on, let's get you cleaned up."

Both children missed the expression on Inu Yasha's face as they made their way back inside the school building.

Fighting was messy, but he was more than willing to get down and dirty to protect his family. No matter what it took.

Author's Note: I'm putting the first two chapters up at once, since this first chapter is OC-heavy. Don't worry, this is the "worst" that gets. The canon characters are still the stars, for all this is AU.