The story is set in the distant mountain village of Okukozome-chō in Japan. Haruka and his twin sister Sora have fond childhood memories of going to the village to visit their grandfather during their summer vacations. However, after losing their parents in a tragic car accident, the two must now move in with their grandfather -- hoping to reconstruct the shards of their shattered lives. The twins get reacquainted with their old childhood friend Nao, their new classmate Ryōhei, the shrine maiden Akira, and Akira's friend Kazuha. All at first seems peaceful and familiar. However, beneath the surface is a secret promise that the twins made to each other long ago, the whereabouts of an important lost item, and the real reason why they chose to come back to Okukozome-chō. As the episodes unfold, new relationships will be created and old ones re-examined.