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He lazily shuffled over to the bathroom, dragging his feet along.



He started brushing his teeth, scratching at his stomach like he usually did.

....Weird. He felt.... thinner than before. What happened to all his belly chub?

Osomatsu spit the toothpaste water into the sink and rinsed his mouth before looking up at the mirror in front of him.

Odd. With those thick eyebrows on his reflection, it's almost like he was staring at....



.....his little brother?



The bathroom door opened, and he came face to face with... himself??





"O-Osomatsu..!?" he heard his own voice exclaim.

"Karamatsu!?" Osomatsu himself said, his voice unusually deeper than usual. "Wh... What's going on!? Why.... Why are you in my body!?"

"I could ask you the same thing!" Karamatsu yelled, sounding higher pitched than he usually did. "What the hell happened!?"


"O-Okay, okay, let's think this through. What did we do yesterday? Something that could have caused this...."

"We.... had gone to assist Dekapan with one of his experiments. We thought that nothing occured, but.... maybe that experiment caused this?"

"Right! Then we gotta get to Dekapan quick! He'll know what to do--"




The two oldest brothers were interrupted by their youngest brother flinging the door open.


"Hey, you two, hurry up! We all agreed to go to the mall today, remember?"


They stared at Todomatsu.







"I don't remember agreeing to going out...." Osomatsu grumbled, pulling off the pajama shirt from the body he was currently inhabiting.


"You were asleep. The rest of us agreed," Karamatsu stated, pulling on a black shirt. "Should we tell the others that we...?"


"No, we can't!"


"Listen, Kara," Osomatsu whispered. "If we do, they'll know we ditched them on earning easy extra money from Dekapan. We can't tell them."

"Oh. R-Right. So what do we do?"

"Well, we'd have to pretend to be each other I guess."


"Do we really need to do that...?" Karamatsu asked as he put on his blue hoodie.





"WAIT A MINUTE--!!" Osomatsu yelled, finally realising the outfit Karamatsu had put on. "YOU CAN'T WEAR THAT!!"

"Eh? Why?"

"YOU'RE IN MY BODY, DANGIT! It'd be super weird if the Osomatsu-nii-san they know wore their Karamatsu-nii-san's hoodie!!"


Karamatsu stared down at his blue hoodie.

" that really a problem?"


"Maybe they won't recognise this as your body, and they'll just think it's me--"

"NO NO NO, THEY'LL DEFINITELY SEE IT. YOUR FACE HAS THICK EYEBROWS. MINE DOESN'T. AND YOUR VOICE IS WAY DEEPER THAN MINE. Also, you're like super ripped." Osomatsu motioned at Karamatsu's body's abs. "Seriously, how'd you get these muscles."



Karamatsu sighed as he complied.








With their younger brothers walking in front, Karamatsu nudged Osomatsu's arm. His own arm. His own body's arm? Whatever.


"Honestly though, we need to find some way to get out of this," he whispered. "The longer we go being in each other's bodies, the worse it might get."

"I know, but you know how our brothers are! They wouldn't want us bailing on--"


"Hey, nii-san, whatcha talkin' bout?" Jyuushimatsu asked curiously as he turned towards them.



"A-Ah, nothing much, my little Jyuushimatsu!" Karamatsu hurriedly said in Osomatsu's voice, rubbing his nose in an attempt to pretend to be his older brother. "Don't concern yourself about it."


Glancing over at Karamatsu, Osomatsu turned to Jyuushimatsu. "It's just older brother stuff you don't need to worry about, Jyuushimatsu," he said in Karamatsu's deeper voice, mimicking one of Karamatsu's cool facial expressions.


"....Okay!" Jyuushimatsu turned back to his other brothers and caught up with them.




"......'My little Jyuushimatsu'? Seriously?" Osomatsu said once Jyuushimatsu was out of earshot.


"F-Force of habit! H-Hey, I don't make faces like that anyway!"

"You totally do! A-And I don't rub my nose like that! You've got it all wrong."


Karamatsu sighed. "If we're going to be in each other's bodies, we're going to need to learn how to act like each other."


"So I have to say painful things...?" Osomatsu complained, dismayed.

"W-Well, nothing too extensive. Just.... be more descriptive, I suppose...? Enough so that they won't be suspicious."


"Well, same to you then," Osomatsu said, poking Karamatsu in the chest. "You gotta talk like me. As long as we don't have any more my little Jyuushimatsus we should be fine. And be more casual. You're too tense."


"R..... Right."



They ran to catch up with the rest of their brothers.






"Osomatsu-nii-san, what do you think about this shirt?" Todomatsu said as he walked up to Osomatsu's body, holding up a collared shirt with a pattern on it.


Osomatsu, in Karamatsu's body, nudged Karamatsu, prompting him to respond.


"A-Ah, it.... I think it would look nice on you, T-Totty!" Karamatsu stated. "It would go well with.... um, your beret!"


Todomatsu tilted his head. "Eh? I didn't show you the beret I bought yesterday yet."


Osomatsu practically jumped into the conversation. "S-Sorry, my Totty, I had already shown it to O-Osomatsu! I hope you don't mind, brother.... I couldn't keep the information to myself!"


Todomatsu smiled. "Oh, no worries! I guess this shirt would look good with that, anyway. Thanks, you two!" he exclaimed cheerfully before going off to the cashier.




Osomatsu let out a sigh of relief. "That was close. We need to be careful, otherwise more slip-ups might happen."

"S... Sorry...." Karamatsu said regretfully.

Osomatsu patted Karamatsu's shoulder. "It's not your fault," he said reassuringly, giving a smile.







One shopping trip and a lunchtime at some restaurant later, the two oldest brothers had gotten restless.

They needed to get out of this, not take a walk in the park.


"I've got it! Karamatsu, work with me on this," Osomatsu whispered, turning to Karamatsu.





"Aaaah, my stomach! My stomach hurts like a burning fury...!!" Karamatsu's body yelled, clutching his stomach.


"H-Huh!? Are you alright!?" Osomatsu's body exclaimed worriedly as he caught his brother.


The younger brothers turned around. "Is something wrong?" Choromatsu asked.


"A-Apologies, brother, I must have e-eaten something bad...." Karamatsu's voice coughed.


"W-We should get you home," Osomatsu's body stated, slinging Karamatsu's arm over his shoulder.


"Yeah, Karamatsu-nii-san, you should go home. There's some tea in the kitchen drawer, it can help," Choromatsu said. "Go get some rest."


"Y.... Yeah."




Osomatsu and Karamatsu turned around to head home as their younger brothers went ahead.


"...How much does it hurt, Osomatsu? Do you need anything on our way home?" Karamatsu asked.


"....Eh? What are you talking about?" Osomatsu said blankly, staring at Karamatsu.


Karamatsu blinked. "What."


"I was acting, Karamatsu," Osomatsu stated, taking his arm back from his brother's shoulder. His own shoulder. Whatever. "Now, we're left alone and we can finally get over to Dekapan's."


Karamatsu pouted. "That wasn't nice, lying like that...."


"...Says the guy who lies all the time."



Karamatsu blinked again. "Huh?"


Osomatsu sighed. "You lie, a lot. Like that time when you kept insisting you were fine when you had a horrible fever, even though I was approaching you directly about it. Or what about that time when you claimed you didn't want to go out to eat, but that was actually because you were feeling really cold and shivery and unwell, and didn't want to leave the house because of that?"


Karamatsu froze. He didn't think Osomatsu remembered all that, that sick and cold. "I-I... C-Can we talk about this later...?"


Osomatsu shook his head firmly. "No. Karamatsu, I want to make something clear."



Osomatsu grabbed Karamatsu's shoulders (his own body's shoulders), forcing him to face himself.


"Talk to me, Kara. Talk to me if you ever need anything. I'm your nii-chan, I'm here to help you. You got it?"


Karamatsu stared at him for a while before chuckling to himself.


Osomatsu was puzzled. "What?"


"S-Sorry, it's just weird seeing and hearing my own body say your words," Karamatsu laughed. "But.... Thank you, nii-san."


Osomatsu stared at him before laughing himself. "You're right, it is weird."







"I'm sorry for troubling you two with this, I was so sure that nothing happened from the experiment...." Dekapan said regretfully, writing some calculations on his whiteboard. "It's going to take me a while to alter the machine to reverse this, but I should be able to get it done by tonight."


"Thanks, Dekapan. Can we get compensation money from this?" Osomatsu grinned, rubbing the underside of his nose.


"'s weird seeing the blue one do that...." Dekapan mumbled.


Osomatsu's grin faded, grabbing at the blue hoodie he was wearing.

It didn't sink in fully earlier, but..... yeah.

He was Karamatsu right now.



".....Karamatsu, let's go home first. We can play something while waiting and come back later."


"Ah... Sure."






".....Karamatsu. Hey, wake up," Karamatsu heard his own voice whisper.


.....Right. He opened his eyes, looking up from the futon.


"Dekapan said he's done. Let's go."



Karamatsu pulled his leather jacket out of the closet and followed his brother out.




Osomatsu shivered as they walked down the street. "Geez, are nights always this cold?"


"Maybe it's because you're in my body?" Karamatsu said. "My body usually has a higher body temperature than everyone else's, right? So everything around me feels colder in comparison."


"That might be it," Osomatsu said with a shudder.


Karamatsu took off his leather jacket off of himself. Off of Osomatsu's body. Whatever. "Here, Osomatsu, you need this more right now."




Osomatsu looked at him for a while before a suspicious grin formed on his face.




"No, my dear older brother, I am not cold!" Karamatsu's body grumbled stubbornly, stopping in his tracks. "Why don't you keep that jacket, Osomatsu?"


Osomatsu's body stared at him. "Osomatsu, why."


"Keep the jacket, Osomatsu," Karamatsu's body repeated with a smile.



Reluctantly, Osomatsu's body slipped into his role. "...Karamatsu," he began, "put on the jacket. You're shivering," he grumbled, shoving the jacket into Karamatsu's arms.


Karamatsu's hands rejected it. "No, brother, I am fine--"


"PUT ON THE JACKET," Osomatsu's voice growled, trying to force the jacket onto Karamatsu's body.



Karamatsu's arms were unexpectedly strong. "Osomatsu, please, I do not need...!"


"Karamatsu, seriously. You're gonna freeze if you don't," Osomatsu's voice said, an unusual angry but concerned expression on his face.


"I don't need it--!"


Osomatsu's hands finally managed to wrap the jacket around Karamatsu's body, and he used the jacket to pull Karamatsu's body towards himself and restrain his movements. He stared him dead in the face.








A "pfffffft" escaped from Karamatsu's mouth before they both burst into laughter.


"Is that what I sound like when I say that!?"

"I look so weird with that face--!!"

"Oh my GOD, I never knew I was like that--"

"I didn't know I could even sound like--"


They both continued laughing with each other, still in each other's grasps. They laughed until they were both out of breath, resting their foreheads on the other's.


"Karamatsu," Osomatsu breathed, bringing his hand to his brother's cheek, "just rely on me, okay? I'm here for you. I'm here to help you."


Karamatsu grinned. "Okay."





The wave of nausea, fatigue and numbness hit them like a freight train.


"A-Ah, I might have forgotten to mention all the side effects..." Dekapan said, seeing the older brothers step out of the machine holding their heads in their hands.


"I'm gonna hurl...." Osomatsu mumbled, covering his mouth with his red sleeve and staring at the floor. Karamatsu said nothing, simply resting his head against the metal doorframe.


"Perhaps you two should stay the night, at least until tomorrow morning."



Honestly, the 'bedroom' Dekapan had provided them looked more like an observation chamber than anything. It probably was, anyway, but they were in no state to complain.


Dragging himself and his younger brother over to the beds, Osomatsu flopped onto his bed.


"S-Sorry, Karamatsu, I think you're gonna have to walk over to your bed yourself--"


Karamatsu landed next to him on the bed.


"...Or that, that works too."




After a few minutes of just laying there, Osomatsu willed himself to lay along the length of the bed, instead of across it, and pulled his brother to join him.


"...Hey, Karamatsu."


Karamatsu lifted his head weakly. ""




Osomatsu paused. Why'd he say his name in the first place? He didn't have any topic to talk about in particular.


Maybe he... just wanted to talk to him.



"...what... is it..?" Karamatsu asked, his voice quiet due to his fatigue.


Osomatsu stared at his little brother for a while before wrapping his arms around him, pulling Karamatsu closer, closing his eyes and sighing.


"....It's good to see you in your own body again," Osomatsu mumbled.

"....yeah... you too..."