It had started as a joke. At least, that was what Rin Hiryū assumed when Ashido Mina’s late-night message lit up the group chat—snacks, games, and an oddly serious warning that “if we don’t do this, Monoma wins.”

He hadn’t planned on going.

Then Kendō Itsuka replied with a thumbs-up and a time.

That was all it took.

By the time Hiryū arrived at the Class 1-A dormitory, the sun was already sinking, and the building felt louder than usual. Shoes were scattered near the entrance, bags tossed aside without ceremony. The common room, normally orderly, had been completely overtaken.

Blankets and pillows covered the floor. Fairy lights were strung unevenly across furniture, casting everything in warm gold. The air smelled like popcorn and sweet soda.

Hiryū paused just inside the doorway, hands in his pockets, quietly taking it all in.

Sero Hanta and Tsunotori Pony were already building a massive fort out of couch cushions, Pony insisting it needed another wall while Sero added tape like he had an endless supply. At some point, they declared it a sovereign nation. There was a flag, so he supposed it was official.

Music played softly in the background. Kaminari Denki looked ready to give up on the speaker system before Shiozaki Ibara fixed it with a single unplug-and-replug.

Near the center of the room, Yaoyorozu Momo sat cross-legged with Honenuki Jūzō over a chessboard. Honenuki tensed, and the floor softened slightly beneath him. A groan came from the fort when one wall sagged.

Not far from Hiryū, his usual group had already settled in.

Kaibara Sen was crouched beside a low table, idly spinning a plastic cup between his palms like it was a nervous habit he couldn’t turn off.

Awase Yōsetsu sat beside him, halfway through attaching two cardboard pieces together with absent-minded precision, muttering something about “fort reinforcements” like he’d been recruited into Sero’s nation without consent.

Tsuburaba Kosei, meanwhile, had taken it upon himself to test how long his Solid Air could hold up as a makeshift snack shelf. A bag of chips hovered suspiciously in midair on an invisible platform.

“Don’t drop that,” Awase warned without looking up.

“I’m not gonna drop it,” Tsuburaba insisted, already sounding defensive.

Kaibara snorted. “You’re absolutely gonna drop it.”

“Am not!” Kosei shot back, just before the solid air shattered, dropping the snacks. (“Damnit” — “Pfft—told you, idiot.” — “SHUT UP!”)

The projector flickered through movie options, but no one could agree. Midoriya Izuku scrolled through files with intense focus, while Shinsō Hitoshi and Kuroiro Shihai suggested horror films with unsettling calm.

In the kitchen nook, Uraraka Ochako and Komori Kinoko giggled over mug cakes. Uraraka floated a few inches when she laughed, and a small mushroom sprouted out of one mug.

No one questioned it.

Truth or Dare had already become unreasonable near the back couch. Kamakiri Togaru was hanging upside down from the railing, dramatically reciting something he called Class 1-B’s anthem, while Kodai Yui’s silent stare kept anyone from escalating further.

Somehow, Todoroki Shōto had ended up in a corner with Monoma Neito. Both held cocoa. Todoroki stared ahead, still as stone, while Monoma spoke like he was giving a debate speech. Bakugō Katsuki stood against the far wall, arms crossed, scowling like he hated all of this.

But he hadn’t moved in a while.

Iida Tenya tried to organize cleanup rotations. It failed immediately, dissolving into karaoke and card games. Hiryū didn’t join anything right away. He simply watched, letting the noise wash over him.

This wasn’t training. No villains. No teachers. Just students—rivals sharing junk food and inside jokes under fairy lights. For one night, it felt like an unspoken truce. Hiryū finally stepped further inside, the door closing softly behind him. And somewhere in the chaos, the night was still unfolding.