Sou Hishigata

Sou Hishigata (菱形窓, Hishigata Sō) is a 17-year-old boy who is Shinpei's childhood best friend. He is the eldest son of Hishigata Clinic, the only hospital on Hitogashima, and is studying to become a doctor. He has a strong sense of justice and regrets that he was present at the scene of Ushio's maritime accident but was unable to prevent it. He has confessed his feelings to Mio twice in the past and was rejected.