Saotome Ranma
From Animepedia
Saotome Ranma is a character from the anime/manga series of the same name (Ranma ½). He is a martial artist who has been trained by his father, Saotome Genma, from a young age. At the start of the series, Ranma is a 16 year old boy just returning to Japan.
The Curse
During a 10 year training trip to China, Genma takes Ranma to a Cursed Spring training ground (Jusenkyo). Springs litter the ground at random intervals, and you are supposed to fight while jumping from raised bamboo shoots coming out of the water. Ranma insults his father, and they do battle.
Genma is the first to fall in a spring, is submerged in the water, but manages to recover and jump out-- as a panda. Shocked by this, Ranma lets his guard down enough for Genma to land a blow and knock him into a different spring. When Ranma emerges, he has also changed-- into a girl.
As the guide explained, "Whoever falls into a spring is cursed with the form of what drowned there." Ranma fell into the Spring of the Drowned Girl, Genma fell into the Spring of the Drowned Panda.
This curse can be reversed if Ranma or Genma come in contact with warm water, but if they touch cold water, they take the altered form again.
