Hiraga Gennai appears in the Android Kikaider 01 series as a historical figure from Japan's Edo period who becomes an unexpected target of the evil organization SHADOW. As a real-life Japanese scientist and inventor known for his work in rangaku, or Dutch learning, the series portrays him as a resourceful thinker whose skills are coveted by the organization. SHADOW creates a time tunnel specifically to send their forces, including Hakaida, back to the year 1776 to capture the inventor. Gennai's capture is deemed essential enough for SHADOW to deploy their Ninja Squad through the time portal to secure him. When Kikaider 01 and Bijinda follow the organization through the time tunnel to the Edo period to thwart this plot, they work to prevent Gennai from being taken. The inventor demonstrates his quick thinking and mechanical aptitude when he successfully unlocks the time tunnel's access mechanism using nothing more than a simple hairpin. This action proves crucial, as it allows the group to return to their original time period after the threat is neutralized. Hiraga Gennai thus serves as a catalyst in this time-travel narrative, showcasing how his inventive nature makes him both a target for exploitation by SHADOW and an unlikely ally to the heroic androids.