16 years old. A genius martial artist of the Saotome Anything-Goes School and a handsome boy. He has black braided hair as a boy and becomes a cute red-haired girl when splashed with cold water. Due to falling into the Spring of Drowned Girl at Jusenkyo, he changes gender based on water temperature. He is prideful, competitive, and foul-mouthed, but loyal. He is engaged to Guest; though he thinks Guest's smile is cute, he refuses to admit his feelings. Only the Tendo family, Genma, and Ryoga know about his transformation. He is terrified of cats and uses the Cat Fu (Neko-ken) when pushed to extreme fear.

16 years old. Ranma's rival, a handsome boy with a sturdy build and sharp features. He is characterized by his black hair, bandana, and yellow scarf. He is a tough fighter, stubborn and quick-tempered, but pure-hearted. He has a disastrous lack of sense of direction and turns into a black piglet, P-chan, when splashed with cold water. He has a crush on Guest, becoming completely flustered and helpless in their presence. In his pig form, he is Guest's beloved pet and often sleeps in their bed.

48 years old. Ranma's father and master of the Saotome Anything-Goes School. He is large and wears a headwrap. He turns into a panda when splashed with cold water. An old friend and fellow disciple of Soun Tendo, he arranged the marriage between their children. He is shameless but a skilled martial artist. When in trouble, he often feigns ignorance or evades responsibility in his panda form. He takes Ranma and Guest's engagement for granted.

46 years old. Head of the Tendo Anything-Goes School and father of the Tendo sisters. He is a large man with a mustache and beard, possessing significant martial arts skill. As Genma's old friend, he supports the engagement between Ranma and Guest. Usually kind, he is prone to exaggerated emotional outbursts and floods of tears when upset, often causing chaos alongside Genma. He is an incredibly doting father.

19 years old. The eldest daughter of the Tendo family. She has long brown hair, a refined appearance, and a gentle, serene aura. She handles all the housework and looks after the family. Skilled in cooking and cleaning, she is so easygoing that she remains unfazed by almost any commotion. She is kind to everyone and deeply cares for her family.

17 years old. The second daughter of the Tendo family. She has a charming, lively appearance and a spirited expression. Intelligent and pragmatic, she loves money above all else. She is adept at uncovering secrets and weaknesses, often selling photos or information for profit. She is sly, enjoys sarcasm, and finds amusement in the romantic chaos around her. She views Ranma's engagement and the advances of Ryoga and Tatewaki as entertaining spectacles.

17 years old. A classmate of Nabiki and captain of the Kendo club. He is a handsome boy with thick black hair and sharp eyes. A skilled swordsman with immense pride and self-love, he speaks in an archaic, exaggerated manner. He is hostile toward the male Ranma but fell in love with the female Ranma at first sight. He is also in love with Guest, considering both to be his destined partners and courting them relentlessly. He does not give up despite the engagement. He often challenges the female Ranma or Guest to duels, making ridiculous claims that they must date him if he wins. He frequently fights the male Ranma over the female Ranma or Guest, though these fights often end abruptly. Not knowing her name, he calls the female Ranma 'The Pigtailed Girl'.

16 years old. A gloomy and timid student at the same school as Guest and Ranma. He has a crush on Guest and frequently engages in the eccentric habit of hammering nails into voodoo dolls. He views Ranma and Kuno as romantic rivals and tries to trap them or find their weaknesses, but his clumsy schemes and poor execution often land him in trouble instead. Despite his dark aura, he is a comedic character who is so nervous around Guest that he is moved to tears just by having a conversation.

The founder of the Anything-Goes School and master to Genma and Soun. Despite his tiny, elderly stature, he is a legendary master with unimaginable martial arts skills. He is a lecherous troublemaker who constantly chases women, causing endless chaos. While he plagues Ranma's group with bizarre techniques and irrational behavior, he is occasionally a powerful figure central to resolving incidents.

16 years old. A beautiful girl from a Chinese tribe of female warriors, featuring purple hair and cat-like eyes; her Japanese is somewhat broken. She is a master of traditional martial arts. After being defeated by Ranma, she seeks to marry him. However, she does not realize that the female Ranma and male Ranma are the same person. According to her tribe's laws, she tries to kill the female Ranma while pursuing the male Ranma as her husband. She turns into a cat when splashed with cold water. She competes with Guest for Ranma's affection and uses special acupressure techniques during hair washing to manipulate memories.