Minori Shirayume is a young woman living an ordinary life as a working professional.

One night, on her way home after working late, Minori encounters a “lone girl” standing in a park.

Due to a promise she made with that girl, Minori finds herself lost in an unreal space.

There, deep within a forest, Minori finds herself collapsed on the ground in the form of a shrine maiden.

Silence and darkness, endless rain, a night sky devoid of stars. Before her stands a large, dark Western-style mansion.

Feeling lost and at a loss, Minori steps inside the mansion, as if drawn by an invisible invitation.