Munehiro Nakagami

He is Shin'ichirō's father and was good friends with Hiromi's father. After Hiromi's father died, he took her in. Unlike his wife, he respects his son's privacy and lets him do as he wishes, saying that "Shin'ichirō is Shin'ichirō". Furthermore, he considers Hiromi to be a member of the family and does not treat her badly like his wife.