Jaune starts to wake up, wondering why his bed is hanging from the ceiling.
He tries to complain about his predicament, but is interrupted by some little girl saying, "Okay guys, who's responsible this time?" It took him a moment to realize that he was the little girl, which wakes him the rest of the way up.
This looks like RWBY's dorm? And there's Blake and Yang! So where's...oh, duh. Well, this is a fresh embarrassment.
"Guys, wake up! Something's wrong!" Jaune jumped down, stumbling on his too-short legs, and crashed into Blake's bed.
"Blake! Wake up!" Jaune shook her arm, knowing that Blake was a heavy sleeper.
"...Ruby? What are you doing in our room?"
"What? Blake, it's not Ruby, it's Jaune! I'm in Ruby somehow!"
"Wha?" Blake looked around. "...What?"
"What's going on?" Weiss sat up. "Oh, we had a slumber party? I forgot all about it! Hey, where's Weiss and Pyrrha and—oh, I guess it makes sense Jaune and Ren wouldn't be here, 'cause they're boys." She sprang from her bed in a very un-Weiss-ey manner. "But Pyrrha should be here."
"Hello," Pyrrha said.
"Hi, Blake! Where's Weiss?"
"Um, Nora?" Jaune said. "You have a ponytail."
"I do? We all did our hair? My ponytail is long. And white, oh. Aw, I thought you were just really good hairdressers. Now I have to be a big meanie! I'm gonna—oh, I bet Ren'll know what to do!" Nora spun about and hurried from he room, barefoot, in Weiss's nightgown. Anyone who knew Weiss would know something was wrong...which was probably for the best.
"Fifty lien says Ren's Yang," Pyrrha said.
Ruby woke up, feeling cheerful, alive, and full of Aura.
"Goood morning, team RWBY!" Ruby tried to roll off of her bed and land gracefully between the imrovised bunk beds, but wound up on her face on the floor, mostly because someone put her bed on the floor, but partly because...
"I had a growth spurt? I must have done puberty! And my voice is deeper, too! ...Something about what I just said doesn't sound right." Ruby pushed herself up and looked across the room. JNPR's dorm, and there was JNPR. But they didn't usually look so confused, and where was—
"Oh. Fiddlesticks. Nora, do you know what's going on?"
"Please tell me this is an elaborate prank," she said, too serious for Nora. "You cut off my ponytail and dressed me in Nora's clothes and—"
Before "Nora"-who-was-probably-Weiss could react, "Weiss"-who-was-apparently-Nora charged into the room. "Reeen!" She hurried over to the bed where a black-haired boy in green was sleeping and shook him.
Ruby vaguely remembered seeing a noisy girl wake up a quiet boy on her first day at Beacon, and later realizing that she recognized Nora and Ren when they met at initiation. Ren just woke up and sat up. This is not what the boy in the bed did. He instead struck out with a fist, grumbled about wanting just ten more minutes of sleep, and rolled over, like Yang did. Weiss, like every other member of Team RWBY, had learned to expect this, and to dodge her fist before once more trying to wake her. "Weiss" did not do so, instead taking the punch on her collarbone. She stared at him for a moment before collapsing, bawling like an infant (and very much not like Weiss).
The boy rolled over again and glanced at the ground. "I made Weiss cry," he said, still half-asleep. The other people in the room (aside from Nora, still crying about Ren having punched her) stared at him for about twenty seconds before he sat up and stared at the ground. He then felt the back of his neck and grabbed his ponytail. "NOOO!" cried Yang.
Headmaster Ozpin had learned to expect the unexpected at Beacon, and had been proved right more times than he cared to count, but this time was the one time he felt entirely justified in not expecting the unexpected.
It started with eight students coming to his office (firmly located in the "school" section of Beacon) early on a Saturday morning. It deepened when he recognized the students and realized they had swapped clothing (a practice about as common on Remnant as borrowing a friend's driver's license is on Earth). Weiss Schnee had switched her clothing more or less completely with Nora Valkyrie (though the latter seemed to be having some difficulty breathing in Weiss's narrow dress), as had Blake Belladonna and Pyrrha Nikos (aside from Blake's bow, Ozpin was not surprised to note). Yang and Ren had evidently reached some sort of compromise, scavenging one of Ren's outfits and two of Yang's. Ren wore Yang's coat and boots and one of her spare pairs of pants, while Yang wore one of her unused jackets and Ren's pants and shoes. Ruby and Jaune, being nowhere near the same height, had merely swapped the former's cape for the latter's armor.
Unusual as these events were, it grew stranger still. If they were to be believed, somehow, their minds had gotten switched during the night. Looking at them, he could believe it. They way they had forced themselves into each others' clothing made sense if they were simply trying to fit their bodies in their own clothing, and the language and mannerisms of each matched those of the student whose clothing they wore.
It was natural for children to go to the nearest authority when faced with an unusual situation. Unfortunately for them, Ozpin was as confused as they were about what caused their predicament and what, if anything, could reverse it. He called for Glynda and Bartholomew and the other teachers (even Peter, who was only slightly more helpful than Ozpin had anticipated). Not one of them had any idea how this might have happened or what solutions were possible, though several related rumors or stories of similar situations.
In the end, Ozpin admitted defeat and began calling their families. These would be by far the strangest Scrollcalls he made in his entire life. Or so he hoped, at least.
That afternoon, the eight teenagers spent more unusual weekend-time in the school portion of Beacon, specifically sparring. They needed to get used to their new bodies, and that was that. They had ordered tailors from Vale to come and give them clothes, so at least they didn't have to put up with ill-fitting clothing.
Ruby had the most to change, as Jaune was adamantly opposed to his body wearing a dress. She managed to get a long sweater and pair of tights that he was willing to accept, however, as well as a larger cloak and boots which fit. Most of the others simply wore clothes essentially similar to those they wore before, though obviously with different proportions. The one difference was that Pyrrha added a red hat to her outfit, to conceal Blake's ears. (Blake continued to wear a bow.)
It would be too much to hope that this was the end of their troubles, of course.
Crescent Rose felt too short and too light. Of course, this was simply because she was approximately ten inches in height, and gone from being more slender than average for a girl to more muscular than average for a young man. She wound up overswinging and throwing herself off-balance with embarassing regularity. Meanwhile, Jaune, her opponent, struggled to even lift his own weapon and shield, let alone fight with them.
Weiss and Nora were more alike in build, but not completely the same. Weiss was a bit thinner, Nora a bit more muscular (luckily for her, most of her strength came from careful use of Aura rather than physical muscle), but the most important difference was that Weiss was left-handed, while Nora was right-handed. Weiss was forced to fight with her right hand, adapting every stance to account for this; meanwhile, Nora adapted with relative ease (mostly ignoring the differences, due to Weiss's partial ambidexterity and Nora's stubbornness), suffering mostly from a loss of control due to expecting a bit more strength to be amplified into starting or stopping Magnhild's motion.
Blake and Pyrrha looked much alike to an observer, but they still had some difficulties. Blakes muscles moved quickly, while Pyrrha's moved hard. The former lacked some of her agility and mobility, the latter her strength and Aura, and both were still somewhat disoriented by changes in their senses.
Yang and Ren were almost complete opposites. The Ember Celica had been made to fit Yang's hands; Ren's were a bit longer and more slender, so they didn't quite fit. In addition, while Ren had a heavily-exercised Aura, his muscles were less-developed than Yang's, meaning that Yang had to push more with her Aura to achieve comparable results. Ren had fewer problems; SMGs were more forgiving to changes in strength and size than gauntlets, and he still remembered all of his Aura techniques. Still, he did not perform perfectly; he was used to having a perfect sense of how his body would react when he told it to do something, and this was thrown off by a number of small changes throughout his body...and the two prominent ones on his chest didn't help matters.
The biggest difficulty the teenagers faced was not one of these obvious ones which they clearly saw. With a couple of exceptions, it would just take a little bit of work with their new bodies to acclimate to their new limbs. No, their greatest obstacle was...muscle memory. Their bodies were, in a manner of speaking, expecting a certain set of movements and confused when they didn't happen. The students had, to varying extents, become dependent on muscle memory (in the same sense that they became dependent on having two arms); without it, they felt lost and confused.
There was one small blessing: They kept their Semblances, though some were altered slightly. For instance, Ruby trailed not red rose petals, but yellow sunflower petals. Even with this, though, it was going to be a long day and a long week.
"Yang..." Jaune said. Well, Ruby. Yang was still getting used to her little sister being...well...Vomit Boy.
"What is it, sis?"
"I need to pee!"
"So? Go to the bathroom."
"I don't know which one to go to!"
...Huh. That was a valid question. The sisters were mentally female, but physically male. Jaune and Ren had the opposite problem now.
"Um...I'll get Goodwitch, one moment. HEY! Miss Goodwitch!"
The teacher came over. "What is it, mister—miss Xiaolong?"
"I need to pee," Ruby said.
"Have you forgotten where the restrooms are?"
"I don't know which one to go to!"
Glynda considered the question for a few seconds. "The men's room."
"Um, thanks." Ruby quickly hurried off to the restroom.
Many students, especially the older ones, slept in on Saturdays and missed breakfast; this meant the cafeteria was largely empty, giving teams RWBY and JNPR a bit of privacy; no one really noticed them. This was not true once lunchtime came.
Teams RWBY and JNPR often ate together; this was not unusual. A number of people noticed that they were wearing different clothing, and several realized that their new clothing was essentially what others on the team usually wore. Those who knew at least one member of the teams well would realize that they weren't acting like themselves...though someone on the opposite team was.
Most were polite or shy enough not to pry too far. Some were too curious, however; no one on the teams felt like concealing their predicament, so they explained what they understood.
It didn't take long for the news to spread through the school. Two teams had switched bodies overnight. Seven promising Huntsmen-to-be and Jaune were set back by having to relearn almost everything.
More than a few wondered if it would happen to anyone else.
Jaune stretched out on his bed, still uncomfortable. A few bits missing, a couple gained...and, of course, everything was a lot bigger now. Jaune was used to being taller than most people, but now he was shorter than them. It made him feel like a kid again. Looking to his left, he saw Nora...in Weiss's body. That was still odd. Jaune wasn't quite sure what to feel about that, or any of it. He loved Weiss, he was sure of it, but would his love stay with Weiss's mind? He certainly hoped so. But Jaune was a girl now; did Weiss like girls? Jaune briefly wondered if he still liked girls (that would cause so many issues if he didn't), but was reassured by looking a bit further at Yang. Well...Ren now...try not to think about that. Eventually, Jaune went to sleep, though not before feeling his own chest.
Blake took off her bow, unusually enough. Today, my team knows I'm a faunus. And JNPR, too. She couldn't help but worry about what they thought about this. And everything else...It could be worse. Ruby and Yang changed genders...that would be a nightmare. She rolled over, trying to get comfortable, when she realized something. My team doesn't know I am a faunus...they know I was. What did that mean, that she was human now? Being a faunus, a member of the White Fang, had been so much of her identity before she came to Beacon. What now? If Blake went to Adam, what would he say? Would he see her faunus heart, or her human body? Would he even...no, she couldn't believe it, not from Adam. Some of the other White Fang, but not him. But then again... "What about the crew members?" "What about them?"
Ren slept. He'd gone through some changes today...but nothing that really changed anything. Probably.
Pyrrha gave up on trying to sleep with the bow on. How does Blake do it? Of course, Pyrrha had trouble sleeping even with the bow off. Every little noise was so much louder, the moonlight and occasional light coming under the door so much brighter. Pyrrha glanced across the room to the former boy at the other end. Jaune Arc...he's still Jaune, but it feels...it's weird, because now he's kind of Ruby, too. Pyrrha didn't think less of girls who liked other girls, but she wasn't one. Was that something she should change? Was it something she could change? Dammit, I'm a warrior, not a philosopher!
Ruby was bothered less by quandaries about her identity and more by simply being uncomfortable. She had gotten her bed to be very comfortable...for someone about a foot shorter and a few inches narrower. Now it all felt wrong. Just like everything else today. It wasn't hard for Ruby to see why Jaune was so clumsy and terrible at everything when she had to use his big, clumsy body for everything. It's not fair. Ruby would have much rather gotten Ren's body, or maybe Nora's or Pyrrha's, instead of Jaune's. Anyone would be better than Jaune...
Weiss lay back in Nora's body, fighting its inbuilt urge to twitch and wiggle. It's like she's on a constant sugar high. Or that I'm just naturally calm and disciplined. Or both. This gave Weiss time to think about things...more time than she needed, or wanted, but time nonetheless. She wondered how her status as heiress would be affected by her new body. The natural response would be to have Weiss remain the heiress, despite her new body...but there would doubtless be those who would rather have Winter be the heiress, or even Nora, if they thought they could control her. (And woe upon those who tried…) Modern corporate culture was in theory much different than the dynastic politics of the First Golden Age...but in practice, there were those who looked to those times for inspiration. And there was never a shortage of ambition in the corporate world.
Nora fell asleep pretty much immediately. She had no real complaints, and felt really tired. If this keeps up, I might need to start drinking coffee. She glanced over to Jaune. He really liked Weiss. Will he really like me now? I hope not, that would be weird. She turned over and looked at Ren. And Ren? Will he like me less because I'm not me? Or...will I like him less because he's not him? I don't think so, but...it hasn't been very long. ...And what about the other way? Will Weiss and Yang like each other now? That would be weird...really weird...and what about Ruby? She's in Jaune now...that would be really creepy… Luckily for Nora, she fell into a dreamless sleep before dwelling on such worries too much.
Yang shifted in her bed, staring at the ceiling and pondering family. Her half-sister, her father, and her missing mother were such big parts of her life; were they still her sister and parents, though? Ruby had an extra layer of complexity, since not only was Yang not so much Yang any more, Ruby wasn't so much Ruby. Ruby seemed to still think of Yang as her sister, but what about Dad? And Mom...If I ever find her, there's no way she'll recognize me. Yang sighed. Being a guy changed a lot of things. People looked at Yang Xiao Long and saw a friendly pretty face, maybe backed by steel. People looked at Lie Ren and saw an aloof, potentially dangerous person; someone to be left alone, not someone to talk with, to trust. Well...not all of that is because he's a guy. Yang sighed and managed to go to sleep, hoping she would wake up in her own body.
Fun fact: Most ambidextrous people are genetically left-handed, presumably because left-handed
people live in a right-handed world. Hence the comment about Weiss's partial ambidexterity.