✨ Pop Rocks ✨

Katsuki is just about to blow the villain away when a blinding red light flares from the palms of a little girl being helped up by Uraraka. It winds itself around the group, hitting Uraraka first then Tsuyu, wrapping its tendrils around Deku’s ankle, caressing Kirishima’s face, then swinging down to Katsuki’s chest. He braces for it, but it feels like warm water trickling into his veins, like something finding a home.

His vision blurs, red then an all-encompassing white, before the world focuses again. The girl is crying, hands balled in front of her eyes, and Uraraka is kneeling in front of her. Wrapped around Uraraka’s ring finger is a red string, whose end sprawls past the confines of the battlefield. Katsuki turns, and there’s Deku’s string, and Tsuyu’s too. None of them are connected, except for Kirishima’s, which unfurls to meet Katsuki’s own. Something hot and thick springs up in his throat.

“A soulmate quirk,” Sero breathes. His string is thick, wound around his finger three times and strung so that it loops around a lightpole and disappears several buildings down the road. “I’ve never seen one before.”

“They aren’t usually this powerful, kero,” Tsuyu supplies.

Katsuki meets Kirishima’s eyes, sees the way they’re a little glossy. “Soulmates?” Kirishima asks.

Only then do their classmates see Kiri’s string, and who it’s connected to.

"Katsuki," Kirishima adds, and Katsuki crosses the battlefield.

Kirishima's hand is warm in his own, and their string bows between them, slack drooping where they're close. "Hah, guess I chose right," Katsuki says, quiet enough that only Kirishima can hear.

His face softens, and he smiles. "You're not mad?"

"Why would I be mad?" Katsuki asks.

"Doesn't this mean..."

"Forever, Shitty Hair. You ain't getting rid of me."