Ranma Saotome: The protagonist of this work, a genius martial artist boy who turns into a girl with cold water and a man with hot water. He is in an arranged engagement with Akane Tendo.

Genma Saotome: Ranma's father. He carries a curse that turns him into a panda when splashed with cold water and possesses an irresponsible and brazen personality.

Soun Tendo: Akane's father and Genma's longtime friend. He is a dojo master who often displays exaggerated emotions while shedding tears.

Ryoga Hibiki (P-chan): Ranma's fated rival who suffers from a pathologically severe lack of sense of direction. He turns into a cute little black pig (P-chan) when splashed with cold water and secretly likes Akane.

Shampoo: A girl from a Chinese Amazon tribe. After Ranma defeated her in a fight while he was a man, she pursued him to make him her husband. She turns into a cat when splashed with cold water. (She is like a natural enemy to Ranma, who is deathly afraid of cats.)

Ukyo Kuonji: Ranma's childhood friend and a candidate for his fiancée who runs an okonomiyaki shop. She dresses as a man and uses a giant spatula as a weapon.

Nabiki Tendo: The shrewd and money-hungry second daughter of the Tendo family.

Kasumi Tendo: The gentle and calm eldest daughter of the Tendo family who handles all the household chores.

Tatewaki Kuno: The captain of the kendo club at a prestigious school who is infatuated with Akane and simultaneously in love with Ranma's female form (the pigtailed girl).

Mousse: One of Ranma Saotome's primary rivals, a member of the Chinese Amazon tribe with a unique personality and pure devotion to Shampoo. His name comes from the hair styling product 'mousse,' and he is Shampoo's childhood friend. He is extremely nearsighted and has very poor vision. He turns into a duck when touched by cold water.