Ranma Saotome, a teenage martial artist, and his father Genma travel to the 'cursed training ground' of Jusenkyo in China. There, despite the warnings of the Chinese guard, they fall into the cursed springs. From now on, whenever Ranma is doused in cold water, he turns into a girl and a cute, well-built redhead at that. Hot water changes him back into a man again, but only until the next time. To make matters worse, his father engages him to Akane Tendo, a girl who hates boys.

Rantarō, Shinbei and Kirimaru are ninja apprentices in the Ninja Gakuen, where first grade ones are called "Nintamas". They must learn everything a ninja must know, but as for our heroes, money, food or playing are more interesting. The series show the everyday adventures of our heroes.