Koichi is a relaxed, passive and whimsical man who chooses not to get involved in arguments. He is sometimes carefree to a fault, in the past he was shown somewhat irresponsible and would rather get drunk on bourbon than teach a class. Despite his attitude, he has been shown to be extremely loyal to his superiors. However, Koichi is also a reliable and quick-witted person with a sharp intuition, which allows him to assess people's talents for Hope’s Peak. Enjoys a stiff drink now and then.