Ranma ½ - Season 1 - Eps 159: The Tendo Dragon Legend
While on their way home from school, Akane and Ranma discover a strange fish in a puddle. Dr. Tofu tells Ranma he should take it home and use it for a class project he has to do. Kasumi invites Dr. Tofu to come stay with them because of the tsunami that is about to hit. Once they get home, they realize the fish is actually an infant dragon. Dr. Tofu learns that the dragons meat will grant immortality, and the Frogman (from episode 100) arrives and tries to eat the dragons meat.
About Ranma ½

Title: Ranma ½
First Air Date: 1989-04-15
Last Air Date: 1992-09-25
Status: Ended
Rating: 8.6/10 (from 1421 votes)
Language: JA
Seasons: 2
Total Episodes: 161
Network: Fuji TV
Genres: Comedy, Action & Adventure, Animation, Sci-Fi & Fantasy
Production Companies: Studio Deen
Synopsis
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.
Cast

Kappei Yamaguchi
Ranma Saotome ♂ (voice)

Megumi Hayashibara
Ranma Saotome ♀ (voice)