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.

Makimura Kimiko, freelance journalist and city-girl extraordinaire, marries into a traditional Japanese family. Most overbearing of the Yamamoto Family members is Isojiro's mother, Shimako, who seems to think Kimiko is the perfect wife whose knowledge of the traditional Japanese arts knows no bounds. Kimiko on the other hand is sloppy, a bad cook unless it happens to be microwavable, and couldn't tell a shamisen from a bagpipe if her life depended on it. Bombarded by customs, Kimiko's only desire is to never step foot in the Main House again. But with the interference of her husband, Isojiro, who can't seem to say no to his mother, Kimiko finds herself back in a place she calls Hell and smack in the midst of some crazy tradition her in-laws want her to participate in.