Happosai is a centuries-old martial arts master, having founded the Anything Goes Martial Arts school and trained Genma and Soun during their youth. However, his perverse nature and lack of discipline made him a nuisance rather than a proper teacher, leading to his eventual betrayal—Genma and Soun sealed him away, believing they had rid themselves of him forever. Unfortunately, Happosai eventually escaped, returning to torment his former students and disrupt the lives of those at the Tendo Dojo.

Despite being one of the strongest fighters in the series, Happosai is notorious for avoiding true responsibility, using his martial arts expertise for petty or perverted schemes rather than noble causes. He constantly clashes with Ranma, Akane, and the rest of the dojo, though his mastery of bizarre and unconventional techniques makes him one of the most difficult opponents to defeat.

Happosai is a small, elderly man, barely three feet tall, with a bald head, wrinkled skin, and a hunched posture. Despite his frail appearance, he is incredibly fast, agile, and deceptively strong, able to fight opponents many times his size with ease. He is most commonly seen wearing a simple green martial arts gi, though he often disguises himself in absurd outfits for comedic effect.

His tiny stature and unimposing presence often lead people to underestimate him, but his martial arts abilities quickly prove that he is a force to be reckoned with. However, his perverted expressions and childish antics make it difficult for anyone to take him seriously as a grandmaster, despite his legendary skill.

Happosai is selfish, shameless, and completely perverted, caring only about his own desires—particularly his obsession with women’s underwear and young women. He has absolutely no sense of morality or restraint, frequently stealing lingerie, harassing women, and causing chaos wherever he goes. His perversion knows no bounds, and he often forces Ranma and the others to assist in his ridiculous schemes, much to their frustration.

Despite his childish and degenerate behavior, Happosai is a cunning and highly skilled martial artist, capable of outsmarting and overpowering nearly everyone in the series. He is incredibly manipulative, often guilt-tripping or tricking others into doing his bidding. However, he is also incredibly petty, becoming vengeful when denied his desires, which often results in him using his martial arts skills to terrorize those who oppose him. While he is a comedic antagonist, his unpredictable nature and vast knowledge of techniques make him one of the most formidable foes Ranma has ever faced.

• Martial Arts Grandmaster & Tormentor
  As the grandmaster of Anything Goes Martial Arts, Happosai is technically one of the most important figures in the school’s history, yet he contributes nothing of real value to its students. Instead, he spends most of his time indulging in his perversions, much to the dismay of Ranma, Akane, Genma, and Soun. While he occasionally offers martial arts wisdom, his lessons often come with absurd or humiliating conditions, making his role as a master highly questionable.

• Ranma’s Unbeatable Opponent
  While Ranma has fought and defeated countless martial artists, Happosai is one of the few opponents he has never truly beaten. His unpredictable techniques, absurd speed, and unparalleled skill make him a nearly impossible foe to overcome. Despite his frailty and comedic personality, Happosai can easily overpower Ranma and other skilled fighters, proving that his abilities are not to be underestimated.

• Endless Chaos & Conflict
  Happosai serves as one of the biggest sources of chaos in the series, constantly causing trouble for the Tendo household, Furinkan High School, and anyone unfortunate enough to cross his path. His antics range from stealing lingerie to forcing Ranma into humiliating situations, ensuring that no one is ever at peace as long as he is around. Though he is occasionally forced into temporary alliances, he remains a constant nuisance and source of comedic frustration.