Shinpei is a kind-hearted teenager who used to live on Hitogashima with the Kofune family after his parents' death, but moved away to Tokyo to become independent soon after. Returning to attend Ushio's funeral leads him down a path of dark secrets on the island. He discovers his ability to loop by dying
Ushio
Mio's older sister and Shinpei's adoptive sister. Unlike Mio, Ushio is bold, brazen and hot-tempered, though this makes her capable of acting quickly and responding to sudden situations. She is often seen wearing a school swimsuit
Mio
Ushio's little sister who has a crush on Shinpei. Unlike Ushio, Mio is shy and meek, and it is these personality and physical differences that have led Mio to harbour much self-hatred.
Hizuru
A horror-mystery writer, Hizuru is intelligent and level-headed, capable of making accurate deductions and detailed planning