It was just a usual day in U.A. when Katsuki had spotted an unexpected text from his parents. His 6 year old little sister was coming to U.A.!!! Katsuki's only weakness was coming to his school! Who knows what disasters await!!! Much Fluff awaits Please read!!
Sister Complex? How about "look at her and I'll kill you" complex? The Bakugou's noticed something missing in their life. One day they decide to adopt a young girl to fill the void they've been filling and hope that the new responsibilities that come with having a younger sibling will tame the wild Katsuki.