Primary

• Ai Natsuki Younger Sister of Rin Natsuki
• Ai Natsuki Twin Sister of Yuu Natsuki
• Ai Natsuki Daughter of Kazuyo Natsuki

Extended

• Rin Natsuki Older sister of Ai Natsuki
• Rin Natsuki Older sister of Yuu Natsuki
• Rin Natsuki Daughter of Kazuyo Natsuki
• Rin Natsuki Best friend of Nozomi Yumehara
• Rin Natsuki Friend of Kurumi Mimino
• Kazuyo Natsuki Mother of Rin Natsuki
• Kazuyo Natsuki Mother of Yuu Natsuki
• Kazuyo Natsuki Mother of Ai Natsuki
• Kazuyo Natsuki Childhood friend of Megumi Yumehara
• Yuu Natsuki Younger brother of Rin Natsuki
• Yuu Natsuki Twin Brother of Ai Natsuki
• Yuu Natsuki Son of Kazuyo Natsuki