Real name: Gorota Kumashima
One of Keita's best friends and the boss of the class. He goes by the nickname "Kuma." He has a crush on his classmate Ai Kobayashi, whom he calls "Ai-tan."

He is rough and simple-minded, but also easily moved to tears and kind-hearted. He loves fried chicken.

His house is on Dandan-zaka, and his family runs a factory called "Kumashima Works." His family consists of his father and mother.