A/N: When I was first watching the Christmas party episode, I DIED when Eri said "trick or treat" and had trouble concentrating on the rest of the episode. Thus, I wondered, "what if another character had the same reaction? What if they found it so funny that they went along with it?", and this story was born.
Nine days ago, there had been an attack on Deika City. However, that wasn't why the members of Class 1-A were gathered in the dormitory of UA High School. Today was a most celebratory day that was observed by many countries around the world: Christmas, and everyone except Katsuki "Kacchan" Bakugo was wearing red or green Santa outfits. The table in the common area was packed with a variety of scrumptious foods that added a sweet, savory scent to the air, and the students were eagerly chatting about various subjects:
"…but you had a ton of people scouting you out for the Sports Fest!" Eijiro Kirishima pointed at Kacchan. "You came in first! You could go wherever ya want to!"
Kacchan turned away. "I'm not interested in learning anything from some second-tier wannabe."
In an attempt to make him seem more festive, Mina Ashido leapt towards Kacchan from behind and attempted to put a Santa jacket on him. However, he sensed the attempt and whipped around to face her:
"YOU TOUCH ME AND YOU DIE!"
"Come on, give in to peer pressure!" said Ashido. "It's Christmas! Where's your festive spirit!?"
"Hard time to do work studies," said Shoto Todoroki.
However, it was clear that not everyone was interested in hero business, least of all Minoru Mineta, who pounded the palms of his hands on the table:
"This is supposed to be a party, you guys, so how 'bout less with the school stuff and more with the holly-jolly!?"
"Dude, what are you, the Yule Police?" said Denki Kaminari.
Fortunately for Mineta, at least Rikido Sato seemed to be into the holly-jolly:
"Come on, you guys! Might sound weird, but Mineta has a point! It's time for us to dig in!"
Speaking of digging in, the rest of the students couldn't help but notice the chicken that Sato was carrying:
"Sugarman can cook regular food!"
The door to the dorms opened, and it would become clear that Class 1-A wouldn't be the only ones getting down with the Christmas spirit:
"Sorry we're late." Shota Aizawa, aka "Eraserhead" popped in. "Have you started the party already?"
The students of Class 1-A turned to face Aizawa, and let out some happy chuckles, not necessarily when they saw him, but when they saw Eri dressed in a little Santa suit:
"I'm supposed to say…'trick or treat'?"
Clearly, Eri's lack of common holiday knowledge proved highly amusing, for Todoroki – who was drinking a glass of eggnog – accidentally spat it up all over Momo Yaoyorozu.
"Ewww, GROSS!" exclaimed Yaoyorozu. "What is WRONG with you!? My Santa outfit is ruined!"
Todoroki couldn't care less, for not only had he dropped the eggnog on the floor, but he was now rolling on the floor laughing hysterically, or what would commonly be known in Internet speak as "ROFLMAO".
"OH MY GOSH!" Todoroki kept laughing. "SHE SAID 'TRICK OR TREAT'!"
It didn't take long for the other students of Class 1-A to take notice of Todoroki's fit of laughter:
"H-how is he laughing?" Izuku "Deku" Midoriya dropped his jaw when he witnessed this most unlikely turn of events.
"Dude, I can't believe Todoroki is laughing!" said Kirishima. "This is GOLD!"
"Todoroki, this is immature behavior!" said Tenya Iida. "Cease your riotous laughter at once!"
"YEAH, YOU'RE NOT EVEN SUPPOSED TO BE FUNNY!" yelled Kacchan.
"WHO CARES!?" Todoroki continued laughing. "I'M HAVING THE TIME OF MY LIFE!"
"Todoroki has gone bye bye," said Tsuyu "Tsu" Asui.
Ochaco Uraraka could only nod at Tsu's observation.
"I am unsure of whether to be amused by Todoroki obtaining a sense of humor or to be disappointed in his loss of control," said Fumikage Tokoyami.
"I dunno, I think he's really cute when he's laughing!" said Ashido.
"I know, right?" said Toru Hagakure. "He's way cuter when he's not all serious!"
"You might think that, but I think this is just sad," said Kyoka Jiro.
Speaking of sad, there was one person who was stricken with utter disappointment when she saw Todoroki laughing his hindquarters off: Eri.
"W-why is he laughing?" Eri was forming tears in her eyes. "I-I didn't say anything funny! Is he…oh no, he's making fun of me!"
Eri ran out of the dorms crying, causing both Aizawa and Deku to take notice.
"ERI!"
Like one of Meat Loaf's bats out of Hell, Deku sprinted out the door and ran after Eri. It didn't take long for him to catch up to her, either.
"Eri, what's wrong?" asked Deku.
Eri continued crying. "The white-and-red guy made fun of me!"
Despite Eri's sadness, Deku smiled. "It's OK! Todoroki didn't mean to make fun of you! He really thought it was cute that you said 'trick or treat'!"
"I HATE HIM! I WISH HE WAS DEAD!"
"Now now, Eri, that's not a nice thing to say! I promise I'll get Todoroki to apologize to you and make everything better!"
"Y-you promise?"
"I promise!"
Deku gave Eri a big hug, which she returned. On one hand, it really hurt for Deku to have to try to comfort her, especially considering that not only had one of his best friends inadvertently hurt her feelings, but also because he thought back to how it took all that effort to help her after being stuck under the shadow of Kai "Overhaul" Chisaki for so long. On the other hand, Deku felt like a hero, knowing that he could comfort Eri with a smile on his face despite the pain.
While Deku was comforting Eri, Aizawa was attempting to restore order:
"Todoroki…"
"BRB DYING!" Todoroki continued to roll around in a fit of laughter.
"Todoroki!"
Todoroki kept laughing, so much so that he was in stitches. "I…I CAN'T!"
"TODOROKI!"
Seemingly out of options, Aizawa wrapped Todoroki up in his Capture Cloth and brought him face-to-face, causing him to stop laughing.
"Have you no respect for schoolteachers?" said Aizawa. "You should show more respect while you're here. I could break you, so leave it."
"Um…" Todoroki was sweating nervously.
"Thought so."
Aizawa released Todoroki, and the festiveness got on as usual.
Later on, Deku was busy cleaning up when Todoroki approached him…
"Midoriya…"
Deku grabbed Todoroki by the collar and slammed him against a wall.
"Todoroki, you son of a bitch! There is NOTHING funny about what you did to that poor little girl!"
Todoroki was sweating nervously. "M-Midoriya…I…I can explain!"
"Explain this: this was supposed to be Eri's first Christmas, and you RUINED it for her with your immature laughing fit! What do you have to say for yourself!?"
"Midoriya, I'm sorry! I never intended to hurt her feelings! I just thought it was really cute that she said 'trick or treat'! Besides…" Todoroki sparkled and made Bambi eyes at Deku. "…you wouldn't be mad at your best friend, would you?"
Deku stared deeply into Todoroki's eyes. On one hand, he was still quite ticked off, but on the other hand, Todoroki seemed to be genuinely remorseful about hurting Eri's feelings, and deep down inside, Deku had always known that he was a good person.
"Actually, Todoroki, I should be sorry, too. It's just…Eri means a lot to me, and I wanted this to be a happy occasion for her." Deku let go of Todoroki.
Todoroki rubbed the spot where he'd been grabbed. "I understand. If there's anything I can do to make this right, please tell me."
Deku smiled. "Well, why don't we let Eri decide?"
Deku looked over at Eri, who was in better spirits judging by the way she was hopping up and down while smiling.
"Hop on Todoroki!" said Eri. "Hop on Todoroki!"
Deku chuckled. "Todoroki, get ready for it!"
"Midoriya, wait…!"
Deku gently shoved Todoroki to the ground, while Eri proceeded to hop on top of him. While Todoroki lamented that this had somehow become part of what he had to do in order to become a hero, he was nevertheless willing to put up with it if it meant that this little girl's happiness and his friendship with Deku would be restored. Eventually, Eri got tired of hopping on Todoroki, so he got up.
"Well, now that we've gotten that out of the way, there was something I wanted to talk to you about…" said Todoroki.
Deku tilted his head slightly. "What's up?"
"I understand that you and Bakugo have been having trouble finding an agency for your work studies. If you don't have choices you like, I was thinking: come with me. Do a work study with Endeavor…the Number-One Hero."
That's right, the laughter's not done yet! Tune in next week when Endeavor gets a taste of his son's silliness!
Criticism is gold. Negativity and nitpicking are pyrite.