Kotaro (コタロー Kotarō)- A boy genius dressed in a cat suit who helps Dr. Go and Mi out by assisting in their inventions or building his own. He has an obsession over Kuro, and tries to prove to be as powerful as him. This idea of his was the result of being an outcast. He is experienced in technology, with an IQ of 200. The reviewer for Manga-News describes Kotaro as walling himself into his world of video games, but also regards Kotaro as an author surrogate. Kotaro is portrayed by Rika Komatsu.