December 24th. The snow had taken the shape of the roofs it had fallen over. The weather was chilly but my living room was warm, thanks to the heater. "Sorry." Just one word sent from his LINE account. It could mean a lot of things.

Highschool student— Souma Ayato never felt the need to know his older sister— Saeko. When she suddenly dies in a road accident, everyone suggests he forgets the incident. Everyone, except his mysterious classmate— Hikari Shimizu, who claims to know Saeko better than anyone else. The two b...