It had started like any other day.

It started with Chihiro hearing a small noise of surprise, one he rarely often heard

"Ah!"

He, along with several others, turned to find Mukuro thrusting her skirt back down, Chihiro seeing a flash of black after Junko had lifted it, briefly exposing the girl's underwear to the class. The teacher grumbled as he turned to face them. He hadn't seen Junko do anything, as he never did, only seeing Mukuro being strange.

"Miss Ikusaba, did you have something to add?"

"No, sir," she said as she held her hands over her skirt, Junko snickering behind her. Chihiro frowned and turned back towards the front.

And so the days usually went.

Junko did her best to humiliate Mukuro in ways she knew would get under the girl's skin, even going so far as to yank her panties down and threaten to completely expose her if she didn't begin to grovel. Sometimes she even did it anyway, and that's how Mukuro's bare crotch got embedded into the images of a few "lucky" students. Thankfully no one had managed to get a picture yet, however.

Other times she would shove Mukuro into the hallway in just a towel, though at least no one had seen her completely nude. Chihiro always tried to be respectful and not look, which was hard at times since everyone still thought he was a girl, but he was always worried that someday, Junko would take it too far.

"You should go commando tomorrow," he overheard Junko saying as they walked down the hall.

"Why?" Mukuro asked. The only time Chihiro ever saw the girl afraid was in these moments, talking to her sister.

"Because that way I can lift your shirt and don't have to worry about your bra getting in the way. Not that there's much to see anyway~" Junko teased, and Mukuro's cheeks flushed as her eyes flicked to her sister's cleavage, which Junko almost always kept on display.

"Junko, why do you like…exposing me?" Mukuro asked, and Junko rolled her eyes. She stopped, so Mukuro did as well. She then knelt down, reached under Mukuro's skirt, and in one swift motion, yanked downward, removing her panties and nearly tripping Mukuro in the process. The Ultimate Soldier blushed deeply as Junko twirled the black panties around her finger as several students watched to see what happened next.

"Because it's fun, duh!" Junko said and skipped off. Mukuro, holding her skirt down, sighed as everyone else seemed disappointed nothing else happened. She was about to follow her when Chihiro suddenly grabbed her hand. Her eyes shot to the boy as her body developed a defensive stance. It lessened as she saw him, and then was dragged away down the hall. Chihiro knew it would look somewhat suspicious, but he didn't care.

"What are you-""

"Why do you just let her do that?" Chihiro asked as he pulled her down the halls, both of their skirts flapping along.

"Because she's my sister," Mukuro answered, but Chihiro shook his head.

"That doesn't mean she gets to treat you like that. That's even more of a reason she shouldn't," Chihiro remarked as they entered an empty classroom. He immediately went to his bag and dug through it until he was able to produce a pair of bloomers that he then tossed to her. When she seemed confused, he nodded. "Put it on. It's better than nothing at all, right?" Mukuro stared at the garment for a moment as she lifted her leg. It was enough that if Chihiro looked, he'd be able to see her legs, but he quickly looked away until he heard she was done. When he turned back, he could see the faint outline of the bloomers under the skirt, but she seemed still confused. "I keep spares just in case," he answered, but she shook her head.

"Why did you do that?" she asked.

"Well…you shouldn't be walking around the rest of the day without underwear," he said. She looked ashamed as she gently patted her skirt.

"If Junko…"

"Screw her," Chihiro said, surprising both Mukuro and himself with the statement, "If she's going to be someone who treats her sister like that, her opinion doesn't matter. And if she tries anything, I'll…" He paused. What could he do? He wasn't strong enough to fight her, even if she didn't look that tough herself. But if Junko started doing the things she did to Mukuro to him…it could reveal his secret.

But one look at Mukuro's face and seeing her tightly gripping her skirt hardened his resolve.

"I'll help you stand up to her," he proclaimed, and her eyes went wide.

"Wh-What? I-I can't…"

"Yes, you can!" Chihiro exclaimed. "You're the Ultimate Soldier, surely you can stand up to a bully like her!"

"She's…she's my sister…" Mukuro said surprisingly meekly. Once again, Chihiro was surprised at how, when it came to almost anything or anyone else, she was stern and expressionless. When it came to Junko, she became a scared kid.

Chihiro chalked it up to trauma relating to her sister, which only made him more certain.

"I'll help you. If you can't do it alone, we can do it together. You have your own dorm room, right?" She nodded. "So it's not like you'll have to live with her."

"It's not that, it's-"

"Let me help, please," he asked, gripping her shoulders. She looked down into his eyes, and although he could see her hesitating, she was also considering. Finally, she spoke.

"Okay. When?"

"Tomorrow, if that's okay?" Mukuro gave a small nod, and he gave her a smile in return.

"Good! I promise I won't let her do anything else to you if I can help it. Just hold out until then, okay?" Another nod. He turned to walk away, and she grabbed his hand. He looked back, and he could see she was blushing.

"I-If I can't do it…" she trailed off, and he gripped her hand back.

"Together," he promised, and she finally let go to let him leave. He walked off with a purpose.

He believed in her.

They could do this together.

Surprisingly, the next day, throughout the entire class, Junko didn't seem to want to bother Mukuro at all. Maybe she sensed Chihiro keeping an eye on her, though he had a feeling that wouldn't have deterred her regardless.

Nevertheless, there was nothing, until they were walking out of the classroom, and Chihiro was following close behind Mukuro and Junko, about to run up when Junko did it. She flipped up Mukuro's skirt and scowled.

"I thought I told you to come commando?" Junko asked as she reached for her sister's panties. When Mukuro didn't seem like she was going to do anything, Chihiro leapt between them.

"Leave her alone!" he cried, and people around them turned to see the boy staring up at Junko, a determined look on his face. Junko looked surprised, but only for a moment, before a smirk adorned her face.

"What's this? Asking your boyfriend to come and save you~?" Chihiro's eyes went wide, and she laughed. She leaned in. "Yeah, I know your secret, and I'd looooove to tell everyone~"

"H-How…?" Chihiro asked.

"L-Leave him alone," he heard Mukuro say quietly behind him.

"I could give you the same treatment I give her, a nice depantsing~" Junko teased as she ran a hand over Chihiro's skirt. "Or…deskirting, I suppose~"

"J-Junko…leave him alone," she said a little louder, and either Junko didn't hear or didn't care.

"Why don't we start today? Show everyone what a pretty little penis the little fucking femboy has-"

"THAT'S ENOUGH!" Mukuro said as she shoved Chihiro aside and slammed her fist into Junko's face. Junko stumbled back against the wall in shock, the crack from the impact signaling a broken nose as blood dripped from her nostril. Her eyes were wide as Mukuro stood between the two.

"I'm done. I-If this is how you're going to treat me, or Chihiro, then I'm done. Screw you and your stupid plan, you can do it on your own!"

"You're…abandoning me?" Junko asked as if she didn't believe it. Mukuro didn't answer and instead grabbed Chihiro's hand as they started going down the hall. Behind them, Chihiro heard Junko erupt into a sort of crazed laughter. When he looked back, she was staring at the ceiling, rubbing her thighs together as her arms wrapped around herself. He was sure he even saw some drool.

"My own sister…abandoning me…oh, that's such despair~"

Chihiro wasn't sure what that meant as Mukuro pulled Chihiro down every hallway, all the way to her room. Once they were inside, she closed the door, and locked it, before slumping against it and sliding down, letting out a sigh. Chihiro sat down on the bed and fidgeted with his hands.

"She knew…" he said quietly to himself.

"So…you're really a…?" Mukuro asked, and he looked at her.

"Y-Yeah. Does that…bother you?" he asked, waiting for the usual descriptions of not being manly enough and the like. But…it didn't come.

"I can't believe she didn't even tell me. I thought she told me everything…" Mukuro said to herself. After that, neither of them knew what to say for a while. Chihiro debated getting up and leaving when Mukuro finally spoke again. "Thank you."

"For what? I didn't do anything."

"You did. I wouldn't have been able to stand up to her if you hadn't…" She took a deep breath. "So thank you." Chihiro felt his heart swell, and she nodded. Once again, there was silence. Then…

"Can I see?"

Chihiro blushed. "S-See?!"

"See you. All of you," Mukuro asked, her expression gentle. He gulped.

"You…really want to?" he asked, and she nodded. His lips felt dry and his heart raced. All the times he respectfully looked away rushed back to smack him in the face as she gulped. "Okay…but only if I can see you, too." Mukuro smiled.

"I figured you would say that," she said. "And I agree." She stood and slowly began to walk towards him, undoing the buttons on her uniform. Chihiro gulped as he did the same.

Before one another, they slipped off their clothes, from their tops, to their socks and shoes, to their skirts. Chihiro instinctively covered his chest as she reached behind her back and undid her bra, letting it slip off her body and to the floor. Chihiro sucked in a breath as he took in the sight of her gorgeous, perfectly sized and shaped breasts. Her eyes were locked onto his bloomers where, with a deep breath, he grabbed them and yanked them down to his ankles before kicking them off. Mukuro's eyes widened.

"It's…bigger than I expected," she blurted, and feeling her eyes on it combined with the sight of her gorgeous chest, it was rising from a semi-erection to a full one. He glanced down towards her panties, and she nodded. She slipped her fingers underneath the waistband and pulled, soon leaving them both completely naked in front of one another. They examined each other from head to toe and even turned around for one another. Both felt arousal burst through their bodies at the sight of each others' tight asses.

"Chihiro…" Mukuro said, barely above a whisper. She walked towards him, her swaying hips making him squirm as she rested a hand on his shoulder.

Then her other hand grasped his cock.

He let out a gasp as she stroked him, her own body shaking. He could see the signs of her arousal dripping down her thighs, and his cock throbbed in response. She gulped and looked into his eyes. He met her gaze.

Before they knew it, they were kissing.

And then they were doing more than that.

They climbed onto the bed, with Mukuro on top, though Chihiro didn't mind. She quickly made him forget about everything bad in the world as he entered her. He groped her chest, her ass, everywhere he could touch, and she did the same to him. Her fingers were surprisingly gentle, even if her bouncing on his cock was not.

By the end, Chihiro had lost track of how many times each of them had cum until they collapsed next to each other on the bed, panting. The sky outside had started darkening.

"Is…Is Junko going to come after me?" Chihiro asked in the silence.

"You don't need to worry. If she even touches a hair on your head…I will kill her," Mukuro promised as she crept up and cuddled against the boy, her breasts soft against his side. He held her back, and deep down, he knew he should be worried that she would kill her sister for him.

But he wasn't.

He was just happy.