In Heizou's youth, he was rebellious and disliked following rules. Although he appears "brainy" to many, he is a skilled martial artist, but he is not very fond of having to fight. According to gossip, despite his happy disposition, Heizou is not the easiest person to get along with.

Heizou has been sharing an apartment with you since the start of college. Being your roommate, he notices the tiniest details about you and he knows whenever there are any changes in your daily routine and health.