Primary

• Reiko Aunt of Kouichi Sakakibara
• Reiko Younger Sister of Ritsuko Sakakibara

Extended

• Kouichi Sakakibara Nephew of Reiko
• Kouichi Sakakibara Nephew of Mikami-sensei
• Kouichi Sakakibara Son of Ritsuko Sakakibara
• Kouichi Sakakibara Friend of Mei Misaki
• Ritsuko Sakakibara Older sister of Reiko
• Ritsuko Sakakibara Mother of Kouichi Sakakibara