Minakami is a small village with mountains surrounding it. With tradition and interpersonal relation still rooted strongly, a big shrine became the center of local activity. There, a legend about a Tennyo and her robe exists.

A university student, Minagami Kousuke, returns to his hometown which he never visited after an incident involving him and his family. He reunites with his once estranged family and friends, and also meets some new ones: Shouko, his cousin who is somewhat cold to him; Iroha, his childhood friend who welcomes him dearly; and Ginko, a mysterious woman who seems to know him in the past. Kousuke spends his time peacefully while working part-time job and trying to improve his relationship with them.

——But one day, a monster called Yamawaro breaks that peace.

The monster attacks Kousuke and he gets hospitalized. Even though he has no major injuries, he notices irregularities surrounding him.

What is the true nature of the monster? Is it related to the Tennyo legend? Why can't Kousuke remember the past? And who is this mysterious woman, Ginko? There is something more to this village than what meets the eyes.

Suddenly, Kousuke's younger sister Sakuya comes to visit him...