In a fight with villains bakugo was hit with a quirk, this turning him to an adult, his whole personality changed since then, everyone is more happy with the new kstsuki as he doesn't scream and gets mad at people, especially deku, anymore. Deku on the other side is getting strange feelings from this new kacchan and tries to avoid them and soon he founds out he's been spending more time with bakugo than he has ever did since kids.