Kotarou

コタロー

Kotarou is one of the series' main characters. A boy genius clad in a black catsuit, he assists Dr. Go and Mi-kun by helping with their inventions or constructing his own. He harbors an obsession with Kuro-chan and strives to prove himself as powerful as him. This mindset stems from his experience as an outcast. He is technologically proficient, boasting an IQ of 200.
Despite being a remarkable genius, Kotarou's lack of common sense is his frequent flaw. Prior to meeting Kuro, he was an avid retro gamer, using his intelligence to mask his loneliness. Although he is very earnest about making new friends, such as Dunk and later Kuro and the gang, his naivety in approaching strangers often lands him in trouble.
Kotaro designed his own black cat costume based on Kuro-chan, but unlike Kuro's standard skin suit, it was equipped with bulletproof and insulative features capable of withstanding high voltage.