Great Mazinger
Shiro is Koji's younger brother. Most of the time, Shiro's role is to add some comic relief to the plot. He remains in Japan when Koji departs at the beginning of Great Mazinger. His character acquires a bit more depth in Great Mazinger, as he becomes acquainted with his father Kenzo, who was previously thought to be dead. Toward the end of the series, Shiro finally bonds with Kenzo, who died shortly thereafter. He even gets to pilot his own robot in Great Mazinger, the Robot Junior.