Kōtarō Wakatsuki is a supporting character from the original 1969 Tiger Mask anime series. He is the son of the founder of the Chibikko House orphanage and the older brother of Ruriko Wakatsuki. After the orphanage fell into financial hardship and temporarily closed, Kōtarō took it upon himself to reopen the facility and manage its day-to-day operations alongside his sister. He is deeply committed to providing a safe and caring home for the children, many of whom are orphans like the protagonist Naoto Date.

In terms of personality, Kōtarō is depicted as a gentle, patient, and kind-hearted man. He never raises his voice at the children, even when the orphanage faces severe financial strain, and he handles the constant struggle to keep the facility running with quiet determination. His primary motivation is the well-being of the children under his care; he works tirelessly to ensure they have food, shelter, and a supportive environment. Unlike the wrestlers in the series, Kōtarō has no combat abilities or involvement in the wrestling world. His role is entirely that of a guardian and father figure to the orphanage residents.

Kōtarō's key relationship is with his sister Ruriko, with whom he shares the burden of running Chibikko House. He also interacts with Naoto Date, though he is unaware that Naoto is the masked hero Tiger Mask. Naoto provides financial support to the orphanage, and Kōtarō gratefully accepts this aid without knowing its true source. Throughout the series, Kōtarō represents the everyday struggle of those who dedicate themselves to helping others, and his steady presence serves as a grounding contrast to the dramatic, violent world of professional wrestling. He does not undergo major personal development, but his resilience in the face of adversity is a constant element of the story. Notable abilities are not applicable to his character, as he is a civilian caretaker rather than a fighter.