Kōji Tongari is a classmate of the protagonist Eiichi Kiteretsu and one of the main characters of the series. He belongs to a wealthy family and lives a comfortable life, but he is notably timid and cowardly, often relying on others for protection or support. Tongari has a strong attachment to his mother, to the point where he is commonly described as a mama’s boy, and he frequently calls out for her in moments of distress. He often acts as a follower to the local bully Kaoru Kumada, known as Butagorira, and the two are frequently seen together. In the early episodes of the anime, Tongari was portrayed as a sly and slightly devious lackey who would side with Butagorira in causing trouble for Kiteretsu and his robot companion Korosuke. Over the course of the series, his role gradually shifted. The voice actor began adding improvised ad-libs to the script, and Tongari developed into a comedic straight man and a tsukkomi who often provides commentary on Butagorira’s antics. He is not particularly brave or athletic, but he does display notable artistic talents. He is skilled at drawing and manga creation, winning a local children’s art contest and even being commissioned to paint a mural for a public bathhouse. Tongari is also playful and romantically fickle, occasionally enjoying pranks on Korosuke and switching between short-lived relationships. Despite his selfish tendencies, he remains a friend of Kiteretsu and occasionally asks the inventor for help using his gadgets. His family background provides him with opportunities such as a private jet and a vacation villa on an island. Tongari’s overall development in the series moves him from a minor antagonist to a more integral part of the group dynamic, serving as both a source of humor and a foil to the stronger personalities around him.