It begins, as all such things do, on a normal enough day lazily hanging out in the dorms. The self-proclaimed Bakusquad lounging around with nothing to do, utterly bored.
"Hey... Do you think Aizawa-sensei has some sort of big secret? Like, he used to be on the wrong side of the law and got reformed or something?" Sero asks, making him ultimately the one to blame for all that follows.
"I dunno."
"I saw him pet a cat once, maybe he volunteers at a shelter?" Kirishima guesses.
"What if he's like secretly really social and just acts grumpy around us? Like, goes out to night clubs and stuff. That's why he's so tired all the time!" Ashido theorizes.
"HAH?"
"I don't know man, I don't think sensei would fake his personality..."
"He seems kinda like a loner, maybe he's got a secret family or kids or something?" Kaminari hedges.
They fall quiet for a moment, contemplating their mysterious teacher when Shinsou pipes up from his position sprawled upside down across the couch with a mischievous grin.
"Personally, I think it's fairly obvious that Aizawa's a vampire and thus spends his off hours avoiding garlic, crosses, mirrors and the sun."
"He is kinda pale..."
"That... kinda makes sense."
"THE HELL IT DOES DUMBASS! WE'VE ALL SEEN HIM IN THE SUN!"
"Ah, but Bakugou, who's to say that wasn't an illusion or that the creatures haven't conquered the sun in our modern era of quirks?" Counters a blatantly smirking Shinsou, wiggling his fingers ominously for dramatic effect.
Before Bakugou can blow up and retort Ashido interrupts.
"You know what this means!? It's time for a Bakusquad investigation!"
"DON'T INCLUDE ME IN YOUR DUMB SHIT!"
-
The camera opens on a grinning Kaminari and Ashido. Sero is behind the camera as Shinsou watches the chaos he's unleashed from beside him. Kirishima trying his best to do damage control to no avail.
"Welcome! To the Bakusquad's First Investigation! Today, we're investigating the mystery of our teacher, Aizawa-sensei, and allegations of vampirism that have recently come to light!" A peppy Kaminari begins.
"We'll be interviewing witnesses and launching a thorough investigation! First, Uraraka, Midoriya do either of you have anything to say about the allegations?" Ashido asks.
"eh? Vampirism? We haven't heard anything about that have we Deku?" Uraraka answers as Midoriya enters into a mumble storm from beside her. "See, no idea, sorry guys!"
"Too bad, what about you Tokoyami?"
"Aizawa-sensei does carry an aura of great darkness, perhaps..."
"You heard it here folks! An aura of great darkness, straight from our resident supernatural expert. Quick! Kirishima write that down!"
The duo slide up one on each side of Todoroki, grinning madly. Kaminari nudges him with an elbow.
"So, Todoroki, got any theories about our Sensei's supernatural origins?"
Todoroki's eyes gain a new glint as he begins, "I thought you'd never ask. Personally, I think Sensei's perpetual exhaustion stems from his natural nocturnal disposition. Operating in the day, while possible, causes..."
By the end of Todoroki's rant which covers everything from nocturnal cycles to how his capture scarf works to disguise his fangs to Aizawa's eye color, even Kirishima's eye are wide. In their shock and contemplation, no one notices how hard Shinsou is struggling to keep from laughing.
-
"So! Here's all our evidence!" Kaminari and Ashido present a messy conspiracy board borrowed from Todoroki they've added their evidence too. Shinsou disappeared somewhere again so Sero is their only audience member. They really should figure out where he goes in the evenings sometime, maybe make that their next investigation.
"We've got Todoroki's stuff, Tokoyami's statement, and that time Asui and Yaomomo saw Aizawa-sensei hanging upside down from the gym rafters last week. Now what?"
Sero raises his hand, "We could test some stuff? Like the garlic thing?"
"Great idea Sero! I have just the plan..."
-
Aizawa Shouta opens his door to see Kirishima, Kaminari, Ashido and Sero standing innocently outside and looking up at him. Instantly suspicious he raises an eyebrow in the way that usually gets them to crack.
"What are you doing here?"
"We made cookies Sensei! Do you want to try one?"
"You... made cookies? By yourselves?"
"Yeah! Bakugou gave us the recipe!"
He takes the offered cookie, it doesn't look poisoned, and he has faith that Kirishima at least to have enough common sense to hopefully not put glue in it or something. The quartet watches with baited breath as Aizawa's face makes a series of fascinating expressions before swallowing thickly and looking at each of them with nothing short of incredible pain in his eyes.
"Kirishima... Please tell me you know better than to put garlic in chocolate chip cookies."
"I thought it would be manly to experiment..."
"None of you are allowed in the kitchen anymore, I can't trust you not to accidentally kill your classmates."
"Sensei that's not fair..." They whine.
"Life isn't fair, get Bakugou to clean up the kitchen and stay out of it until further notice. Now if you'll excuse me I'm going to brew another pot of coffee and drown myself in it."
-
The group slumps on the way back, each disappointed with the results for their own reasons. Kirishima because Aizawa-sensei didn't like their cookies. Kaminari because now that he's banned from the kitchen he can't make his breakfast concoctions. Sero and Ashido because they couldn't tell if his reaction was "garlic is bad in chocolate chip cookies" or "I'm a vampire who can't have garlic." The dejected group finally makes it back to the kitchen to find a terrifying sight.
Bakugou is standing behind the counter holding a single cookie in his hands. It has a small bite in it.
"What. the. fuck. do you think you're doing? I gave you the simplest recipe I have, nothing too difficult, impossible to fuck up. Or so I think. I leave you alone for ten minutes and you put fucking garlic in it? I lined up all the ingredients on the counter for you!" His admonishments are quiet, which only makes it more effective. All four of them cower before the wrath of a chef scorned, not even able to spit out a single excuse.
"If I find out this was about that vampire shit..."
"It's not I swear!" Ashido finally finds her voice.
He narrows his eyes and they wisely run before he can ask any more questions.
-
They decide to wait a few days for the smoke to clear before enacting the next part of their investigation: crosses.
None of them want to do this part directly so Kaminari comes up with a brilliant plan. All it takes are a few well placed words within earshot of Shiozaki from 1-B and they're set.
Shinsou, with Eri on his hip, walks up next to the spying squad and watches curiously from a distance as Aizawa awkwardly speed-walks away from a cross-wielding, enthusiastically evangelizing Shiozaki.
"So... what's all that about?" He inquires.
"Distaste for crosses," whispers Ashido from her spot behind a bush.
"That's two done, only one thing left to test." Kaminari reports from next to her.
"What are you testing?" Eri asks curiously.
"Nothing you need to worry about Eri," comes Kirishima's sheepish answer.
"Speaking of Eri, since when does Aizawa-sensei let you watch her? He hardly lets anyone in 1-A get close without him." Ashido pouts.
Shinsou just shrugs, hikes Eri higher on his hip and walks off. She waves goodbye and loops her arms around his neck.
"He's so lucky."
-
Next came mirrors, they had decided early that the sun was a wash. They had all seen him in direct sunlight at least once, Bakugou had them there. Ashido went shopping and found a large mirror for real cheap. They snuck into the 1-A classroom one evening to attach it to the back of the flippable whiteboard, Aizawa-sensei already had a lesson plan written up on the back side so hopefully he wouldn't check before class started the next day.
It was going great, they'd nearly finished attaching the mirror when they heard someone open the door and peak into the room. Ashido shrieked in surprise, unbalancing the others and nearly causing them to drop the whole thing.
Peaking in and sniffling miserably stood Eri, desperately trying to wipe her eyes.
"What are you doing here Eri? Are you ok?" Kirishima, characteristically, is the first to recover and attempt to soothe the upset little girl. The others frantically trying to set the mirror down without dropping it.
"I lost 'Toshi! I can't find him! and UA is so big! What if I never find him!?" She bursts into tears.
"uhm, 'Toshi? Does she mean Shinsou?" Sero asks.
"awww, why does Shinsou get a nickname? no fair." Ashido pouts.
"Focus!"
"Right, Eri, where did you last see him?"
"We were going to the teacher's lounge and there was this pretty butterfly and suddenly he wasn't with me anymore!" Eri struggles to hold back more tears as she recounts her story.
"Alright guys! New mission, find Shinsou, let's go!" Ashido leads the charge.
"uhhh, he's already on his way over. I texted him like right away." Kaminari bursts her bubble with not a hint of subtly.
A few minutes of sitting and comforting Eri as best they can and Shinsou stumbles in, looking haggard.
"Toshi!" Eri runs into his arms sobbing out apologies. He picks her up and quietly soothes her, giving his own apology for not realizing she wasn't with him sooner. Their audience feeling awkward and like they're intruding on a private moment they were never intended to see.
Eventually they both calm down and Eri, exhausted from her little adventure, starts to nod off on Shinsou's shoulder. Her arms still hugging him tightly.
"Thanks for finding her, I was freaking out when I realized she was gone." He rubs the back of his neck awkwardly. "What are you guys doing in here anyways?"
"MIRRORS!" Ashido shouts, perhaps a bit too loud.
"Huh? you know what, don't tell me I want plausible deniability." Shinsou walks off to put Eri to bed.
-
The next day sees the triumph of the last part of the investigation. Sero, Ashido and Kaminari all agreed that their results had been inconclusive thus far but hopefully this would prove Aizawa-sensei's vampiric nature.
The lecture starts off normal enough, Aizawa going through announcements before declaring that, instead of a practical lesson, they would have an extra long lesson on hostage situations and proper protocal. He walks over to the mobile whiteboard and flips it over.
A few things happen all at once.
First, Aizawa realizes his lesson plan is nowhere to be seen.
Second, the mirror catches the sunlight at just the right angle to send painful amounts of light into his eyes, momentarily blinding him and causing him to hiss in pain.
Third, Aizawa reflexively activates his quirk out of instinct.
Fourth, the backlash of using erasure on himself knocks him out and he collapses to the floor.
Fifth, the students start screaming bloody murder
...at least their teacher isn't going to get a headache from the noise.
-
"So, what have we learned?" Aizawa's glare is no less terrifying now that he's been banned from quirk usage for the time being.
"Don't investigate your teachers for being vampires." Comes the dejected answer of several members of the Bakusquad. All standing thoroughly cowed in the infirmary between the combined efforts of Bakugou and Aizawa.
"What? No? I was going to say think about the consequences of your actions. I thought this was a poorly thought out prank, you think I'm a vampire?"
"It's not our fault Sensei," Ashido whines, "Shinsou's the one who came up with it." She points at him, apparently feeling no remorse at throwing him under the bus.
Aizawa's turns his neck in a rather unsettling fashion to face Shinsou, previously innocent and blameless.
"So, Shinsou. Care to tell me why my students have been trying to assassinate me lately?"
"We weren't trying to assassinate you! That's totally unmanly!" Kirishima protests.
Aizawa ignores him and continues to stare Shinsou down.
"Wait, is that why you put garlic in those cookies?" Shinsou breaks eye contact and turns back to his friends. "Thank you, he looked more done with life than he had in weeks, it was great."
"Shinsou..." Aizawa sighs.
"Oh, right, they were speculating about you having a big secret and I kinda thought it would be funny." He shrugs, "I had no idea it would go this far."
Aizawa looks to the ceiling in exasperation, it offers him no help.
"Alright, I can't believe I have to say this but from now on there will be no investigations into your teachers. My private life and any secrets I may or may not have are my own and as I think you've just demonstrated, sticking your nose in things that aren't your business can have some unintended consequences. I want 500 words on the potential harms of baseless rumors and knowing when to leave well enough alone by Friday."
"Wait..." Kaminari speaks up, "How would Shinsou know how Aizawa-sensei looked after we gave him the cookie? He was in the teacher's dorm and we couldn't find Shinsou anywhere?"
"Yeah! Where have you been disappearing to?" Ashido joins in.
"Uhhhh..." Shinsou obviously struggles to find an explanation.
"Let me amend my statement, from now on there will be no investigations into your teachers or peers. Leave. It. Be." Aizawa sends each troublemaker a warning glare. They wisely drop it and apologize sheepishly.
-
Later that night sitting on Bakugou's bed Shinsou speaks up as he absently braids Eri's hair.
"Do you think they'll ever figure it out?"
"If those dumbasses haven't figured it out yet there's no hope for 'em."
"Eh, you're probably right."
Shinsou smiles a little as he finishes the braid and heads off to dinner at the teacher's dorm with his sister.