TV-Series
Description
Mari Nikaidō is a human character from Japan who first appears in Kinnikuman as a teacher at Suminoe Kindergarten, known as Himawari Kindergarten in the anime adaptation. She is introduced as the original love interest of the protagonist Kinnikuman, and both he and his young sidekick Meat quickly develop feelings for her. Kinnikuman affectionately calls her Mari-shan, while she grows to care for him deeply in return.

In terms of personality, Mari is depicted as a gentle, graceful, and composed young woman, often described as a Yamato nadeshiko type. She has a calm and nurturing demeanor, which suits her role as a kindergarten teacher. Despite her generally soft-spoken nature, she has a lively side and frequently engages in playful arguments with her friend Natsuko, though the two later become close companions. Her kindness and patience are evident in how she treats the children at the kindergarten as well as Kinnikuman and Meat.

Mari's primary motivation throughout the early story is her affection for Kinnikuman. She supports him in his endeavors and often cheers for him during his battles. However, when the character Bibinba is introduced and becomes a rival for Kinnikuman's attention, Mari feels overshadowed and chooses to step back rather than compete. This decision leads her to leave Japan to study early childhood education overseas, putting her romantic feelings aside for the sake of personal growth and allowing Bibinba to take over the role as Kinnikuman's love interest.

Her role in the story varies between the original manga and the anime adaptation. In the manga, Mari appears mainly during the first three story arcs and fades from prominence after the American Expedition arc. In the anime, she remains a more consistent presence throughout the series, continuing to appear in later arcs and eventually becoming Kinnikuman's official girlfriend. By the end of the anime's Kinnikusei Oui Soudatsu-hen arc, she and Kinnikuman become engaged and marry, with her acting as a supportive and loyal partner.

Mari maintains significant relationships with several key characters. She is close friends with Natsuko, with whom she often collaborates during the series, and she shares a warm bond with Meat, who is also fond of her. Her relationship with Bibinba is somewhat distant, as she gracefully steps aside to allow Bibinba to become Kinnikuman's partner in the original story. Later, in the sequel series Kinnikuman II, Mari returns to Japan after her father's death and takes over the running of Suminoe Kindergarten as its principal. She has an adopted daughter named Rinko, whom she raises with love and care. Rinko later becomes the love interest of Kinnikuman's son, Mantaro, connecting Mari to the next generation of the story.

In terms of development, Mari's character grows from a simple love interest into a more independent and resilient woman. She sacrifices her personal desires to pursue her education and career, eventually building a life for herself and her adopted daughter. Despite never marrying, her enduring affection for Kinnikuman remains a quiet thread throughout her life. She does not possess any superhuman abilities or combat skills, as she is an ordinary human. However, she demonstrates intelligence and resourcefulness; in the anime, she occasionally provides commentary and analysis during matches, helping to explain the action to the audience. Her strength lies in her emotional support, loyalty, and nurturing nature rather than physical prowess.
Cast