The hentai master of Saotome Genma and Tendo Soun when they were still in training. He is probably the most lecherous person in the world. He comes to the Tendo dojo to find his students and the one to inherit his anything-goes martial arts school, which Genma presents to him in the form of his son, Ranma. He loves to chase girls, steal women's panties, and bug Ranma.
Although Happosai is very old and about 2 feet tall, he is very good at martial arts. Nobody can beat him (possibly with the exeption of Cologne), although Ranma can kick his ass pretty good.
Like Genma, he is also the source of some of the problems occurring in the dojo, and many
people also come there trying to kill him.
Women's underwear and their *ahem* body, is his source of power. If he hasn't seen or touch one in a long time, he loses strength, and looks even older than he is right now.