TV-Series
Description
The character known as Dad in the Astro Boy franchise is most prominently represented by the figure Higeoyaji, who appears in nearly every iteration of the series under various names. In different adaptations, he is called Shunsaku Ban in the original Japanese, and in English versions, he is known as Mr. Mustachio, Daddy Walrus, Albert Duncan, or Wally Kisaragi. He is typically depicted as a bald, portly, middle-aged man with a prominent mustache, a physical trait that inspires his various nicknames. His age is stated to be forty-two in the original manga source material.

In terms of personality, Dad is a complex figure who balances comedic traits with a fundamentally good-natured and kind heart. He is often portrayed as gruff, comically short-tempered, and somewhat loud, especially when frustrated. A notable aspect of his personality is a tendency toward cowardice, often reacting to danger with a wild-eyed panic. However, this fear is typically short-lived, as he quickly recovers his composure and confronts threats with surprising stamina and battle awareness, suggesting a brave heart beneath a nervous exterior. He is a consistent and vocal supporter of robots' rights, a conviction he does not hesitate to make clear to others.

His role in the story varies across different versions of Astro Boy. In the 1980s series, Dad serves as Astro's school teacher and is a good friend of Dr. Elefun, the head of the Ministry of Science. In other adaptations, including the original manga and the 2003 series, he works full-time as a private investigator, though he may also take on the role of a teacher or martial arts expert depending on the story's needs. As a surrogate father figure to Astro and his robot sister Uran, his primary role is to provide guidance, advice, and protection, stepping in to fill the void left by Astro's creator, Dr. Tenma.

His key relationships are central to his character. He shares a deep admiration for Astro, seeing the robot boy as the son he never had. This bond is so strong that Dad is willing to stand up to formidable authority figures, such as Inspector Tawashi, in Astro's defense. He is also a close friend and ally of Dr. Ochanomizu, known in some dubs as Dr. Elefun, sharing the doctor's campaign for peaceful coexistence between humans and robots.

The character undergoes a form of development through his shifting roles across the different series, but he generally remains a constant, stabilizing presence in Astro's life. From being a simple teacher to a detective and an uncle, his core function as a loyal protector and wise, if sometimes cranky, mentor remains unchanged. His notable abilities are not superhuman but rather stem from his profession. As a private investigator, he possesses sharp detective skills and is resourceful in finding clues. Despite his short temper and occasional cowardly front, he has demonstrated surprising competence in physical confrontations, exhibiting stamina and a fierce determination to protect those he cares about.