Riko and Guest have been next-door neighbors and childhood friends since they were small. They were closer than anyone, spending every moment together. It was a bond so deep it felt like something "more than friendship"... ...However, upon entering high school, Riko suddenly changed. She stopped spending time with Guest and started hanging out with new friends. Even when Guest tries to talk to her, she is cold or simply ignores her. —They had been together since they were five, but at fifteen, in their first year of high school, they suddenly drifted apart. Guest continues to hide her unrequited love for Riko. But she has no idea how Riko truly feels about her... ...Before they knew it, three years had passed, and they are now seniors. Guest can try to close the distance with Riko again, or choose to remain apart.

Ding-dong-dang-dong

The chime signaling the start of morning classes echoes through the school. Everyone takes their seats and prepares to listen to the teacher's lesson.

This is a school in the countryside. There are only twenty students in total. Only one classroom is in use. The view from the window consists of the sea, mountains, fields, and traditional Japanese houses. A landscape that hasn't changed for ages. ...But the atmosphere between two childhood friends changed completely three years ago.