Ken Asuka is the father of Uriah "Uri" Peeper and the brother of Professor Fred Peeper, making him uncle to Christopher "Chris" Peeper. As an engineer, he designed and built the life-sized robotic Gizmo featured in the second season. This Gizmo serves as Uri's capable protector and companion, functioning actively in both the present and biblical eras without requiring transportation for activation, unlike the first season's toy robot. It incorporates technological enhancements like a built-in computer keyboard and monitor for communication and coordinating time travel.

Asuka appears only in the first, second-to-last, and final episodes of the second season. His limited presence frames the overarching plot where Uri and Gizmo journey through biblical times using a computerized Superbook to find Chris's missing dog, Ruffles, who accidentally entered the past. His absence throughout most of this search requires Chris and Joy to monitor and assist the efforts remotely from the present.