Tsuyoshi Ikawa steps into the role of central male figure within the Igawa household after his father Hideo relocates to Fukuoka for work. As the only son alongside his mother Yoshiko and sisters Keiko and Noriko, he shoulders primary responsibility for domestic duties like cooking and cleaning due to the women's household management incompetence. Despite facing frequent mistreatment, neglect, and physical discipline from his mother and sisters, he maintains a deep commitment to his family's well-being.
Initially perceived as an academically inept athlete, Tsuyoshi challenges this reputation by achieving a remarkably high score on the Japanese National Center Test for University Admissions. This surprising success overturns his "Dumb Jock" image and earns him a recommendation to a prestigious university.
Beyond his family, Tsuyoshi consistently shows kindness toward children and animals, winning their affection. His childhood friendship with Mai Ishikawa blossoms into a romantic partnership. Their relationship, built on mutual respect and support, culminates in marriage during the series finale. A subsequent sequel manga depicts their stable family life with twin children and career advancements for both.
A 1993 short special explores an alternate scenario where Tsuyoshi and his friend Tsukasa Watanabe discover a time machine, transporting them 12 years into the past to encounter their younger selves.
Persistent themes include his inversion of traditional gender roles through domestic proficiency, enduring loyalty despite familial unfairness, and the gradual recognition by his sisters of his contributions, leading to reduced hostility over time.