Primary

• Erika Toudou Step-sister of Yuuto Toudou
• Erika Toudou rival of Sayaka Ichinose

Extended

• Sayaka Ichinose In love with Yuuto Toudou
• Yuuto Toudou Step-brother of Erika Toudou
• Yuuto Toudou In love with Sayaka Ichinose