Ashibe's Father, whose given name is Mizuhiko, is a central figure in the Ashibe household. He works as a carpenter, a profession he pursues with dedication and considerable skill. A defining trait is his Edokko, or traditional Tokyo working-class, personality, which is immediately recognizable by his rough, forthright manner of speaking and his habit of wearing a headband and a belly warmer. Despite this down-to-earth exterior and his blue-collar job, he possesses a surprising and often humorous secret: he is the only son and heir of the chairman of a large corporation, Ashiya Shoji. He is a Cambridge University graduate, which stands in stark contrast to his chosen life as a craftsman living in a modest apartment. This background occasionally surfaces in his behavior, as he sometimes exhibits the sensibilities of a wealthy heir, such as thinking of Las Vegas casinos when he hears the word gambling or constructing a hidden wine cellar in the apartment basement.

Ashibe's Father is a skilled and enthusiastic carpenter, but his passion for his work often leads him to take on ambitious projects without seeking permission. He has a habit of repeatedly renovating and expanding the family apartment, which frequently results in him being scolded by their landlady. His projects can be quite elaborate; on one occasion, he built a vast hidden room complete with a kitchen, bath, and toilet inside a client's vacation home, and he has even built a pond in his own yard. At his core, he is a loving and present parent to his son, Ashibe, and his wife. He cares for the family's pet seal, Goma-chan, although he has a peculiar way of showing it, sometimes using the seal as a pillow, a hand towel, or even a tool for waking people up. His relationship with his own wealthy father is also notable, as he has clearly chosen a different, more humble path in life, working with his hands as a carpenter rather than taking over the family business. This choice is treated with respect, even if it is a point of curiosity for others.

Motivated by a strong work ethic and a desire to provide for his family in his own way, Ashibe's Father represents the value of forging one's own path over simply inheriting a life of privilege. His role in the story is to be the quirky, well-meaning, and slightly eccentric patriarch. He is the source of much of the physical comedy in the series, often through his overzealous construction projects and his unexpectedly grand ideas about everyday life. While he might seem like a simple tradesman, his background as a corporate heir adds a layer of irony to his character. His development is not about dramatic change but about the consistent and loving performance of his chosen role as a father and husband, balancing his innate grandiosity with the simple joys of family life. His most notable abilities are his exceptional skill as a carpenter and builder, and his talent for getting into trouble with the landlady for his unsanctioned renovations.