If Mina Ashido could describe herself in one word it would be, Love expert. That's actually two words, but that's not the issue at hand. That's why the moment she found out that Bakugou was in a relationship she made it her life's mission to find out who he was dating. This is also why Mina feels absolutely betrayed.
Bakugou had been 'subtly' staring at Todoroki for the past three days. Every time he did it he'd immediately look away with a faint blush on his face (that blush was actually because Bakugou had hidden a scandalous photo of Izuku in his textbook, but nobody needed to know that). It wasn't noticeable if you weren't watching which would explain why nobody had noticed before. So, Mina sent out a spy to see if they were seeing the same thing she was.
Iida reported back positive. Bakugou was definitely staring down Todoroki. In a romantic way or an 'I'm going to kill you' way? That's the real question. Was the first in command of the Zero Investigation, actually a double agent? Had his loyalty been a ploy to cover the fact that he was actually Zero the Hero? Was this what betrayal feels like?
Then again assuming things is unfair. Maybe Bakugou just has a cold? Maybe he was plotting murder? Maybe there was something wrong with his neck? Those would all be better reasons than Bakugou dating Todoroki.
But Iida said he saw the same thing! Iida thought it looked like a crush just as much as she did! And that's because it makes complete sense! Todoroki really didn't talk much about his hobbies, so could he be hiding them? Plus, Bakugou claims to hate him but doesn't treat him as aggressively as he does Midoriya. Although, Midoriya is his brother, but if he just doesn't like having Midoriya around and he acts like that then wouldn't he be just as aggressive to someone he genuinely hates? Todoroki is also pretty smart and definitely isn't athletically incapable...
Oh my gosh. Todoroki had played her like a fiddle.
Thus the Bakutodo faction was formed.
~~
Kirishima felt that out of all of 1A, he knew Bakubro the best. He and Bakugou had bonded through the class, he was even able to get away with calling him 'Bakubro'! So, why exactly had it taken him so long to see the answer that very obviously placed in front of him?
Bakubro was dating Mina!
Bakugou constantly talks about her at lunch! Whenever he tries to talk to him it's just "Oh, Mina would like that," or "Mina is pretty good at this," or the occasional "Man, Pinky isn't totally ugly". That's the definition of Bakulove! He's utterly smitten!
Even Denki had noticed how strange it was. They kept a tally of how many times Bakubro said 'Mina', 'Pinky', and 'Raccoon' during lunch, and the tally was over 60! That's totally manly! They're perfect together!
Mina is also a dancer! That makes so much sense. How did everyone miss this?
Thus the Bakumina faction was formed.
~~
Mineta would never call himself an observant man, but when it came to hot women, he would never miss a detail. So someone explain to him why it looked like Midnight was trying to wink at Bakugou, and why was Bakugou winking back at Midnight. She even walked over to him, whispered in his ear, and then slipped him a note!
That lucky bastard! He was dating Midnight!
Mineta couldn't believe it. How could he? Bakugou got to touch Midnight's boobs! Why not him? Mineta was much more dedicated to her than Bakugou had ever been! He knew Midnight's exact cup size!
Sero had also been watching the whole ordeal and realized that "Holy fuck. Midnight was flirting with Bakugou,". What a lucky man! Sero would kill to get a babe like that!
After class, both boys had realized what was going on and rushed off to find a teacher. The first teacher they happened to stumble upon was All Might. That poor, poor imbecile.
"All Might! We have a question for you!"
"And what is that, my boy?" All Might put on his signature smile.
"Okay so, there's been this whole search to find out who Bakugou is dating, right? And we noticed that Midnight and Bakugou have been REALLY flirty. Like Bakugou is basically eyeing her up and Midnight is returning it. So, has Midnight mentioned having a boyfriend at all?" Sero asked. Sero really hoped it wasn't true, how could he live with the fact that he's done... unsavory things with a photo of his best buds girlfriend?
"Not that I've heard of, young man. But she recently mentioned that she couldn't wait to get back home to be with her 'Cute and feisty little blondie'. I don't think that's much but that might help you in your search..." All Might words slowly stopped. His jaw dropped and his widened. "Holy shit."
Holy shit indeed.
Thus the Bakunight faction was (regrettably) formed.
~~
Now, Tooru wouldn't necessarily call herself a gossip, but she would call herself socially well-informed. She would also call herself a big fan of yaoi manga. She had studied for years for the chance to put her fangirl yaoi skills to work. So when she found out that Bakugou was Bi and was dating someone she immediately knew who her first suspect was.
Kirishima Eijiro.
He was the only option! Out of everybody in class Bakugou openly respected him and let Kirishima call him 'Bakubro'. At one point he even saw Bakugou let Kirishima hug him! With minimal explosions! If that's not a romantic hidden gay relationship then she doesn't know what is! It was like Junjou Romantica all over again!
After making her discovery Tooru immediately went to her boyfriend, Masahiro to spill what she found. He agreed that it made a lot of sense.
Thus the Bakukiri faction was formed (Bakugou didn't even have to interfere to make that happen).
~~
Shouji would never say that he likes to eavesdrop, but he does happen to have unfortunately good hearing. Bakugou also happens to be alarmingly loud when he talks, so it's no surprise that when Bakugou walked by him mumbling aggressively, he heard it all.
"I swear to god if she doesn't call me I'm going to go fucking insane. She's too cute to be this feisty! What the fuck is wrong with Itsuka, why isn't she in class?"
ITSUKA? KENDO ITSUKA?
Shouji didn't mean to snoop, but when you put such important information in front of him he's obviously going to run to the first trust-worthy person he sees and spill so he doesn't have to carry the burden alone! This is why Kouda is now watching Shouji panic sign about how it makes a lot of sense for him to be dating Kendo. She's athletic, tough, and super smart, so why wouldn't she be Zero?
Goodness this is a lot
Thus the Bakuken faction was formed.
~~
Tokoyami wouldn't say he was one for conspiracy theories, but he was one for survival. So, when Todoroki stormed into his room at exactly 3:45 in the morning, he decided that his best chance of survival was to just believe him. Todoroki looked like he hadn't slept in days, his hair was a mess, his eyes were crazy, and his smile was utterly manic. Tokoyami was just going to play along.
Todoroki had spent the past 48 hours trying to prove his theory: Bakugou is dating Monoma Neito.
It hadn't taken him too long to figure out who Bakugou was dating (he was an expert at this). All it took was one look at Bakugou as he passed Monoma in the hallway for him to realize it. It was just too easy.
Todoroki had run to Tokoyami's room as soon as his slideshow was prepared. He spent hours explaining that Monoma and Bakugou act very similar which would be explained by them spending lots of time together. He mentioned that they were both blondes which doesn't mean much, but it would make them more symmetric as a couple. At some point, he had even pulled up an old Egyptian hieroglyphic that had what looked like fire next to a cat, obviously referencing explosions and a copy cat. It was full-proof.
Tokoyami reluctantly agreed. Truthfully, he just wanted to go back to bathing in the endless dark abyss.
And thus, the Bakumona faction was formed.
~~
Katsuki would never say that he was as clever as his fiance, but he has his moments. Even if said moments were only caused by him trying to channel his jealousy into something helpful.
Katsuki had been having a fantastic time talking to his momma (Inko) about wedding plans for after high school when Round face had grabbed him and dragged him off to the common room. The common room right next to the kitchen. The common room next to the kitchen that happened to be where Froggy, Ponytail, and Aux Cord were sitting. Oh, he was gonna play this up nicely.
"So, what did you need from me this late, Uraraka? Hopefully nothing obscene," Bakugou said as calmly as possible. He made sure to make it clear that he was using her name rather than a nickname.
"Um, I was just wondering about Deku? Like what kind of places he likes to go," Pink cheeks muttered, a bright blush on her face. Oh, Katsuki knew exactly what this was. He didn't like it one bit. He was most definitely going to warn Zu as soon as this bullshit is over.
"Oh? I see you're trying to get in good with my brother, huh? You want him to like you or something?" Katsuki said. -Hopefully, that sounded like she wants his approval to date... Zu is gonna be so proud-
"I-i yeah. That would be pretty nice. So, do you know anywhere he would like to go out to?" She stuttered. Katsuki really hated this.
"Well, we usually go out to that mochi place a couple of blocks over. I'm sure he'd like to go there," Bakugou shrugged and then left. He was over the conversation. Hopefully, it was easy enough to take out of context.
Yaomomo wouldn't call herself one for making assumptions, but that conversation sounded way too much like Ochako and Bakugou were dating to not assume. Was Ochako trying to get Izuku's blessing? Did Izuku really not know who his brother was dating?
By the looks on the other girl's faces, that assumption was pretty reasonable.
And thus, the Bakuchako faction was formed.
~~
Now, Izuku would never say that he enjoys lying to his friends, but when he found out that 3 people hadn't joined a side he had no other option. He had to make one last group for total chaos to be achieved.
Izuku wanted to see just what he could get his classmates to believe, so he chose the most random possible option to make the last faction. Aizawa.
"OH MY GOD! YOU GUYS" Izuku ran into the common room, eyes blown wide and looked frantically at the 3 in the kitchen (Ochako, Sato, and Yuuga), "I-I think that Kacchan is dating Aizawa?"
"Oh? Pourquoi?" Izuku felt kind of concerned that the only question was why and not 'what are you smoking'.
"I was talking to Momma and she said that Katsuki was going to be bringing over a special friend over the weekend. And I was really excited because I thought that I was going to get to meet Zero and then Aizawa showed up!" Izuku yelled, "He sat really close to Katsuki too! And my parents were quizzing him like they were trying to interview him for something. It was so weird! But, it would also explain why Kacchan felt the need to hide his relationship. And Aizawa is an underground hero, so he's probably really acrobatic and smart... It makes too much sense!". Did any of this happen? Not at all. Was Izuku tempted to laugh? Very much. Was Aizawa gonna end him for this? Only if he could catch him.
Izuku looked at his stunned classmates. He was really going to have to apologize for this eventually, but right now he was enjoying every second of it. Ochako's jaw was dropped, Yuuga had dramatically gasped and was now mumbling in french, and Sato seemed to be stress eating the cake he had recently baked. Oh how Izuku loved chaos.
Thus, The Bakuai faction was formed.
~~
Aizawa was very proud of Midoriya. His plan so far had been flawless and he was happy to help in any way he could. There was nothing better than the compilation of faces the kids made when they realized who Bakugou was dating. His personal favorite was the clip of Todoroki storming to Tokoyami's room.
The last step to dividing the class had honestly been the easiest. He just needed to call a class meeting (All Might included), make some bullshit announcement, then sit in the corner and watch as Midoriya and Bakugou released the Kraken. It was beautiful.
"So have any of you dumb fucks found who Zero is?" Bakugou announced after Aizawa had slinked off around the corner. Aizawa wouldn't say it, but the synchronized 'yes' that came from the class was pretty impressive.
"I spent days working on this. You are definitely dating Monoma," Todoroki announced.
"No! That's completely wrong! I heard him talking in the halls! He's dating Kendou from 1-B!" Shouji spoke up.
"Don't go trying to cover it up now Todoroki! I know you're a double agent! You're dating Bakugou!" Mina yelled. How clever, Bakugou and Midoriya had turned them on each other.
"What? No! I've done so much research on this topic, it's obviously Kirishima he's dating!" Hagakure said.
"No! I'm not dating Bakubro! He's manly and all, but he's dating Mina!" Kirishima yelled.
"Blasphemy! I founded the Zero mission I would never turn on it!" Mina cried.
"Oh? Then I suppose you're just a double agent then." Todoroki huffed. That was petty.
"Guys please stop fighting! Me, Jiro, and Tsu have all come across some evidence that makes it very clear that he is dating Ochako!" Momo calmly (calmly as in calmer than the others, but she was heated about this too). Aizawa didn't know how Bakugou had managed this, but he deserved extra credit.
"Children! Please stop fighting! I had a conversation with Young Mineta and Sero that seems to show that he is dating Midnight!" All Might boomed. All Might is too gullible for his own good.
"Um. All Might, I-i don't mean to correct you, but... I'm pretty sure he's dating Aizawa," Midoriya piped up. Midoriya would be expelled if this wasn't fun.
And then began the fighting. It started with people getting sassy with others, then there's was shouting, then a quirk went off and people got really angry. Ochako had floated Mineta to the ceiling, Kouda was rapidly signing at Momo, Shouji had made multiple mouths and ears to have multiple arguments, Tsu and Hagakure looked ready to attack each other, Todoroki had pulled up his PowerPoint and was attempting to yell over the chaos, and several members were just screaming while others cried. Meanwhile, Bakugou and Midoriya had snuck off and were laughing their asses off.
Needless to say, Aizawa let them move their seats around the next day when Mina asked. The room had broken into factions with Bakugou at a lone desk in the corner of the room.
That night Aizawa had a large meeting with the staff (Bakudeku included) and watched a highlights reel of all the events that had taken place during Operation: Drool over the School.
And thus, the Bakudeku faction sipped their tea and laughed.