Five Months in Her Skin

The first thing Atsumu noticed was that his pillow felt wrong. Too soft. Or maybe his face was too light against it. The second thing was that his hair was in his mouth. He swiped it away with a groan, then froze.

His hand came back with a long strand of honey-blonde hair. Twice as long as it should’ve been. He sat up so fast the room spun. The sheets slid down, and he felt something on his chest—not muscle. He looked down.

Two gentle curves rose under his oversized t-shirt. He caught his breath. Scrambled out of bed, nearly tripped over the hem that now hit his knees. In the bathroom mirror, a girl stared back—same sharp eyes, same arrogant tilt of the brows, but softer. Rounder. Her hair fell past her shoulders in a messy golden wave. His jaw used to be angular. Now it curved into something delicate.

He pressed a hand to his chest. Definitely breast tissue. Slid the other hand down, between his legs. Nothing. Absolutely nothing. A hollow, unfamiliar space where his dick should’ve been.

“What the hell,” he whispered. His voice was higher. Lighter. Still his, but different. “What the hell?!”

He stumbled out of his room and down the hall, slammed open Osamu’s door without knocking. Osamu was sprawled on his futon, one arm flung over his face, dead to the world.

“Osamu! Wake up!”

Osamu grunted and rolled over. “Go away.”

“I can’t go away! Look at me!”

Osamu cracked one eye open, then the other. Blinked. Sat up slow. His face went from groggy to confused to something like mild alarm. “Who are you?”

“It’s me, dumbass! Atsumu!”

Osamu stared. His gaze traveled down Atsumu’s body, then back up. “No way.”

“Yes way! I woke up like this!” Atsumu gestured wildly at himself. “Look! My hair’s long! I got—I got boobs! And…” He lowered his voice, cheeks burning. “Downstairs is gone.”

Osamu rubbed his eyes and looked again. “You’re still wearing your old shirt. It hangs different. And your shoulders are narrower.” He stood and walked a slow circle around Atsumu, like he was inspecting a weird artifact. “Your face is the same but… softer. Can you still set?”

“What kind of question is that? Of course I can still set! That’s not the point!”

“It’s a little bit the point. You’re still a setter.”

Atsumu wanted to argue, but Osamu’s calm acceptance knocked the wind out of him. No screaming, no panic—just that steady, observant gaze. So Osamu. Atsumu felt his shoulders drop a fraction. “I don’t know what to do.”

“First,” Osamu said, “you should shower. I’ll find you some clothes. We got that bag of hand-me-downs from Auntie last year. There might be a bra in there.”

“A bra?!” Atsumu’s voice cracked. “I don’t wanna wear a bra!”

“Your shirt says otherwise.” Osamu pointed. The thin cotton showed two distinct peaks. Nipples standing up, sensitive from the morning chill. Atsumu crossed his arms over his chest, face burning.

“Fine. But don’t look at me.”

“Wasn’t planning to.”

The shower was a nightmare. Atsumu turned the water hot and stood under the spray, trying not to think too hard. But thinking too hard was all he could do. The weight of his new chest shifted when he moved. He had to brace against the wall to keep from wobbling. His hands felt smaller. His legs were smoother. And when he reached between his legs to wash, there was nothing to grab—just a soft cleft and a tiny nub that sent a shock of sensation through him when his fingers brushed it.

He jerked his hand away. “What the hell was that?”

The nub—he’d read about it, knew what it was called—was hypersensitive. He touched it again, experimentally, and a sharp pleasure-pain shot up his spine. His knees buckled. He gripped the shower caddy and breathed hard. This was going to be a problem.

He finished quick, wrapped himself in a towel, and padded back to his room. Osamu had left a stack of clothes on his bed: a white school shirt, a green skirt, a pair of white socks, and a pale pink bra with thin straps.

Atsumu held up the bra like it was a live snake. “I don’t know how to put this on.”

“Figure it out,” Osamu called from the hallway. “We gotta eat in fifteen minutes.”

After four tries and one nearly strangling himself with the clasp, Atsumu managed to get the bra on. It felt like a cage. The underwire dug into his ribs, and the cups pressed his new breasts into an unfamiliar shape. He put on the shirt and skirt, then looked in the mirror. The girl from before stared back, now in a school uniform that actually fit. The skirt was shorter than he’d like. The buttons strained slightly over his chest.

He walked downstairs, arms stiff at his sides, every step making his breasts bounce under the fabric. Distracting. Unsettling. He could feel his nipples rubbing against the bra, stiff and sensitive.

Osamu was already at the table, pouring two bowls of miso soup. He glanced up, took in the uniform, and nodded. “You look like a girl.”

“Thanks, Captain Obvious.”

“Sit down. Eat. You’ve got practice after school.”

“I can’t go to practice like this!”

“Why not? Coach won’t kick you off just ‘cause you’re a girl. You can still set better than anyone else on the team.”

Atsumu opened his mouth to argue, but the words died. Osamu was right, and he hated it. He sat down, winced as the chair pressed against his breasts, and took a sip of soup. The heat was comforting. Osamu sat across from him, eating silently, watching him with those quiet, knowing eyes.

“Stop staring,” Atsumu muttered.

“I’m not staring. I’m observing.”

“Same thing.”

“It’s really not.”

Breakfast was tense, but Atsumu managed to eat. The whole time, he was hyperaware of his body. The way his shirt brushed his stomach. The way his legs felt bare and smooth under the skirt. The way his chest rested against the table when he leaned forward. Everything was wrong, and yet nothing hurt. It was just… different.

After breakfast, Osamu handed him a pair of gym shorts. “Put these on under the skirt. For the wind.”

“You thought of everything, huh?”

“Someone has to.”

School was worse. First period was a blur of whispers and stares. Atsumu Miya had come to class dressed as a girl, and everyone noticed. Some thought it was a prank. Others thought he’d lost a bet. A few girls whispered that he actually made a pretty good-looking girl, and Atsumu didn’t know whether to feel flattered or mortified.

By lunch, the news had spread. Suna Rintarou found him in the hallway and circled him with the same analytical gaze Osamu had used. “Interesting look. Is this a permanent change?”

“I don’t know,” Atsumu snapped. “It just happened this morning.”

“Hm.” Suna poked his shoulder. “Your form is off. Your center of gravity’s shifted. You’ll need to adjust your jump float serve.”

“I know that!”

“Just saying.” Suna walked away, hands in his pockets, as if talking to a suddenly female classmate was the most normal thing in the world.

It was the Inarizaki way, Atsumu supposed. Roll with it. Get better. Move on.

But moving on was hard when every time he walked down the hall, his chest bounced and ached. By third period, his nipples were raw from rubbing against the rough fabric of his bra. He slipped into the bathroom and adjusted the cups, but nothing helped. He wanted to rip the bra off and just let his breasts hang free, but Osamu had told him that would be worse. More sensitive. More visible.

At practice, Coach Kurosu took one look at him and said, “Same drills. Hit the ball, don’t let the ball hit you.” The team treated him like nothing had changed—except for the confused glances when his voice came out higher. Atsumu’s sets were still perfect, but his serves lacked power. His legs were shorter. His back didn’t arch the same way. He got frustrated and slammed the ball into the net.

“Easy,” Osamu said from the side. He’d come to watch, a towel over his shoulder. “You’re tensing your shoulders. Relax.”

“I’m trying!”

“Try harder. Or take a break.”

Atsumu glared, but he did take a break. He sat on the bench and watched his teammates spike and block, feeling like a stranger in his own skin. Osamu sat down next to him, close enough that their knees almost touched.

“It’s only been one day,” Osamu said quietly. “You’ll get used to it.”

“I don’t want to get used to it! I want to go back!”

“I know. But until you do, you gotta live in this body. And I’ll help you.”

Atsumu looked at him. Osamu’s face was sincere, his eyes soft in a way they usually weren’t. “Why are you being so nice to me?”

“Because you’re my twin, dumbass. Even if you’re a girl right now.” Osamu bumped his shoulder. “You’re still annoying as hell, but I got your back.”

For the first time that day, Atsumu felt a tiny knot of tension loosen. He didn’t say thank you. He didn’t have to.

The first week was a crash course in being female. Osamu did research—quietly, on his phone, when he thought Atsumu wasn’t looking. He learned about bras, about how to measure for the right size, about how to deal with chafing. He learned about menstruation, about ovulation cycles, about the difference between period pain and regular cramps. He learned so much that Atsumu started to feel guilty.

“You don’t have to do all this,” Atsumu said one evening, watching Osamu fold a pile of laundry that included three new sports bras. “I can figure it out.”

“I know you can. But you’re bad at it, so I’m helping.”

“Rude.”

“True.”

On the third day, Atsumu discovered something that made him lock himself in the bathroom for two hours. It started as an itch. A strange, low ache between his legs that built and built until he couldn’t ignore it. He touched himself, curiosity driving his fingers, and the sensation exploded like a firework. He gasped, knees buckling, and had to brace against the sink.

He did it again. And again. And again.

By the time he came out, his legs were shaking and his face was flushed. Osamu was leaning against the hallway wall, arms crossed.

“You okay?”

“Fine,” Atsumu croaked.

“You were in there for a while.”

“I said I’m fine!”

Osamu didn’t push. But later that night, he brought Atsumu a glass of water and a protein bar. “You need to eat more. Your metabolism’s probably different now.”

Atsumu took the bar without comment. He was too embarrassed to say thank you, but he ate it anyway. The truth was, his body was a foreign land, and he was exploring every inch. Some of it was terrifying. Some of it was… interesting. He didn’t want to admit that there were moments he liked the softness of his skin, the way his hair smelled when it was clean, the gentle curve of his waist.

But the worst part wasn’t the body. It was the way boys looked at him.

At first, it was just glances. Then stares. Then comments under their breath. Atsumu had always been confident, loud, untouchable. But now, with a chest that bounced when he walked and hips that swayed, he felt exposed. Vulnerable. He caught a group of third-years staring at his ass while he bent to pick up a ball, and he turned around and snapped, “Got a problem?”

They laughed and looked away, but the damage was done. Osamu saw it too. The next day, a package arrived from an online store. Osamu handed it to Atsumu without explanation. Inside were three bras: two sports bras and one lace-trimmed bralette.

“For comfort,” Osamu said. “The sports ones are for practice. The other one is for when you want to feel pretty.”

“I don’t want to feel pretty.”

“Then wear it for the support.” Osamu shrugged. “Your boobs hurt less when they’re not moving.”

Atsumu tried on the sports bra first. It felt like a warm hug. His breasts were held snugly against his chest, and the bouncing stopped. He almost cried. He didn’t, but he almost did.

“Thank you,” he said, the words rough.

“Don’t mention it.”

A week later, Atsumu got his first period.

It happened in the middle of math class. A dull ache in his lower back, then a warm gush between his legs. He froze. Looked down. The chair was clean, but he felt wet. He knew what it was. He’d read about it, heard about it from the girls on the team. But knowing and experiencing were two different things.

Panic rose in his throat like bile. He raised his hand, told the teacher he felt sick, and bolted to the bathroom. In the stall, he pulled down his skirt. The white panties were stained red. Bright, fresh blood. He stared at it, breathing fast, his hands shaking.

He couldn’t go back to class. He couldn’t fix this. He didn’t have anything.

His phone buzzed. A text from Osamu: You’re late for lunch. Where are you?

Atsumu typed with trembling fingers: I got my period. In class. Bathroom. Help.

Three dots appeared immediately. Then: Stay there. I’m coming.

Five minutes later, a knock on the bathroom door. “It’s me.”

Atsumu unlocked the stall. Osamu slipped in, closing the door behind him. He carried a paper bag. From it, he pulled a packet of pads, a fresh pair of underwear, a pair of sweatpants, and a small tube of pain relief cream.

“Lift your skirt,” he said calmly.

“What?”

“I need to show you how to put the pad on. Unless you already know how.”

Atsumu’s face burned, but he lifted his skirt. Osamu opened the pad, peeled off the backing, and handed it to him. “Stick it in your underwear. Wings go over the sides. Then put the fresh underwear on.”

Atsumu did it, fumbling but managing. The pad felt weird, bulky. But when he pulled up the clean underwear and then the sweatpants, he felt safer. More contained.

Osamu handed him a wet paper towel. “Clean up your leg if any got on you. Then take these.” He held out two ibuprofen and a bottle of water.

Atsumu took them, swallowing dryly. “How did you know what to get?”

“I asked the nurse. Told her I had cramps and my friend needed supplies.” Osamu’s lip twitched. “She gave me a whole lecture on menstruation hygiene. I know more than I ever wanted to.”

Despite everything, Atsumu laughed. It was a shaky, pathetic sound, but it was real. “You’re ridiculous.”

“You’re welcome.”

They stood in the cramped stall, and Osamu reached out to rest a hand on Atsumu’s shoulder. “It’s okay. This is normal. You’re okay.”

Atsumu let out a breath. For the first time since the transformation, he felt like maybe he could survive this.

The months passed. Spring turned to summer. Atsumu learned to live in his new body. He found that he liked the way his hair curled at the ends. He liked the way his voice could go soft and sweet when he wanted. He liked the way Osamu made him ginger tea during cramps, and the way they watched movies curled up on the couch, Atsumu’s head on Osamu’s shoulder.

The fluff was small but significant. A shared bowl of rice. A quiet “you look nice today” from Osamu that made Atsumu’s heart do a strange flip. A hug after a tough practice, where Atsumu could rest his cheek on Osamu’s chest and feel his steady heartbeat.

It was almost domestic. Almost comfortable.

But Atsumu still wanted to go back. He missed his old body. He missed the way his serves felt, the power in his jumps, the ease of walking without a bra. He missed being a boy.

On the last day, he woke up feeling different. The weight on his chest was gone. He sat up, touched his flat chest, reached down, and felt familiar anatomy. He was back.

He ran to Osamu’s room. “I’m me again!”

Osamu was already awake, sitting up, watching the door like he’d been waiting. He took in Atsumu’s broad shoulders, his angular jaw, his short hair. A slow smile spread across his face.

“Took you long enough.”

“Five months! I can’t believe I was a girl for five months!”

“You were a pretty one, though.” Osamu stood and walked over. For a moment, they just looked at each other. Then Osamu opened his arms. “Come here.”

Atsumu stepped into the hug. It was rare, this kind of thing. They were twins who communicated through insults and shoulder-bumps. But now, Osamu wrapped his arms around Atsumu and held tight.

“I’m glad you’re back,” Osamu said against his hair.

“Me too,” Atsumu murmured. “But… thanks. For everything.”

“Yeah. I know.”

They stood there, breathing together, the memory of five strange months settling between them. They wouldn’t talk about it much after this. They’d go back to being the Miya twins, loud and competitive and annoying. But something had changed. A deeper understanding. A bond forged in blood and bras and period cramps.

When they finally pulled apart, Osamu’s eyes were a little wet. Atsumu pretended not to notice. He was too busy doing the same.

“Now,” Osamu said, clearing his throat, “you owe me for all those pads I bought. You’re paying me back.”

“What? No!”

“Yes. That stuff is expensive.”

“You’re the worst.”

“And you’re still annoying.” Osamu grinned. “Welcome back, Atsumu.”

Atsumu grinned back, full and bright and real. “Good to be back.”