Following the death of predecessor Dr. Richard Smith (alias Dr. Hamaguchi), Professor Sakunji—known as Doctor Hook—assumes command of Camp Big Falcon. Trained as Dr. Hamaguchi’s successor, he holds a foundational role in the Earth Defense Force's scientific leadership. Initially perceived as cruel and excessively strict, Hook enforces rigorous, high-risk training regimens for the Voltes V team, pushing their physical and mental limits with life-threatening maneuvers and confiscating personal belongings deemed mission distractions. These methods provoke such tension in the live-action *Voltes V: Legacy* that the team nearly resigns.

Beneath his stern exterior, Hook demonstrates unwavering commitment to Earth’s defense and the team’s safety, clarifying that his orders avoid unnecessary risks while prioritizing civilian welfare above all. This duality emerges when he guides the team to victory during a crisis after their rebellion, promising to value their lives while demanding excellence. Mutual respect gradually develops, enhancing their coordination and performance against extraterrestrial threats.

In *Voltes V: Legacy*, Hook debuts amid a Boazanian attack on Camp Big Falcon, devising emergency configurations to reactivate the base’s barrier—showcasing technical expertise under duress. Unlike his anime counterpart, this version engages directly in combat, participating in a gunfight against antagonist Eva Sanchez after exposing her as a conspirator.

Hook advances Voltes V’s technology, including a new weapon system. Initial failures resolve after he receives updated blueprints from General Danbei, solidifying his role in enhancing the mecha’s capabilities. His leadership blends philosophical conviction with high charisma, attracting loyalty despite an austere demeanor.

Spin-off media like AWA, XP4, and TWA fictions schedule Hook for future appearances, though specific storylines across these extended universes remain undeveloped.