Kazuma moves to the country town of Yamabi Kochou together with Ayumu, his younger brother, due to the latter's weak constitution. On the way to Yorodzuyo, the inn in which they are lodging run by their father's old friend, they become lost in the unfamiliar rural environment. Further, a minor incident leads Kazuma further up the mountain...

There in the depths of the mountain, a girl appears before him...