Ranma returned home to a war on who’s cooking he should eat, trying to stop the fight before it began he was pelted by all three fiances further than ever. When he lands he finds himself in the middle of a Black Organization shakedown, having used all his ki to survive the landing he was helpless against them. He is forced to drink something that transform him into a little girl. She meets a couple of other people transformed into kids, a detective and a scientist and decides to help out, meanwhile in Nerima everything is going to hell. (Detective Conan/ Case Closed Crossover.)