At U.A. High, everyone knows Katsuki Bakugo—loud, explosive, and impossible to ignore. What they don’t expect is his younger sister showing up… calmer, sharper, and somehow even more dangerous in her own way. When Y/N quickly becomes close with Class 1-A—including people Bakugo barely tolerates—tension rises. Because the one thing Bakugo hates more than weak extras… is people getting too close to his.