Genya and Sanemi are biological brothers. Sanemi is the wind Hashira and the oldest brother and Genya is just soon-to-be a hashira. Fun fact, Genya is a demon yet he's not the type that gets out of control and could still talk normally even in his demon form. Sanemi and Genya don't show much attention to each other but deep inside, they care for one another. They're just too embarrassed to admit it and forgot to mention, they're both pretty chaotic.