Ranma is chasing Happosai through a typhoon when she is blown trough the window of a mansion and crashes into a mirror. When she wakes up, she finds she has been split and their is a male version beside her. When the storm blows over, the Ranma’s find that a lot of Nerima has been badly damaged and so they help in the relief effort, feeding people, finding water and shelters, saving Dr Tofu from the Yakuza.