Keita Suminoe

Keita is a third-year junior-high school student studying for his high school entrance exams and although he is the younger brother, it is obvious he is the most mature of the three siblings. He wants to enter the same high school as his older twin step-sisters Ako and Riko, and to do so must study hard while getting help from his sisters as well as he was originally planning on relying on his track running scholarship for another school. While at first he initially dislikes himself for becoming attracted to Ako and Riko, he later becomes proactive in his desires.