Suguru Koshigaya

Birthdate: April 11
Height: 171 cm

Suguru is a third-year middle school student of the Asahigaoka Branch School. He is Yukiko's eldest son, and Natsumi and Komari's elder brother. Even though he is the only male student of the school, he doesn't speak much and has very little presence. He is always willing to do what other people ask him to do and allows his younger sister Natsumi to influence his actions. He is shown to be able to play the electric guitar, piano, and create an elaborate figure using modeling clay.