Ken Sonada, age 49, is a mad scientist with good intentions. Over the course of the series he fulfills the role of father figure to the younger characters, dashing commander of the Sonada army, and kooky but lovable mad scientist. He easily gets wrapped up in his work often forgetting to change clothes, shower, eat, and pretty much everything else.

In the original world, he has one daughter named Mitsuki Sonada and is still in love with his ex-wife Ayuko. In the alternate world, he has no family but forms a bond with Akane Yamano as the series progresses.