Back when Katsuki Bakugou was younger, he had an older sister named Himiko Bakugou. Ah.. back when he actually used to be a pretty nice kid. But one day, after Himiko got her quirk, she just… disappeared. This made Katsuki angry, and gave him his attitude and rudeness today. Fast forward, he’s on a training course with Class 1-A, when suddenly, a few portals show up and the League of Villains shows up, including… Himiko?