Once upon a time in a far, far away place, there were two lands.

The world was divided into an inner land and an outer land.

People feared the outer land inhabited by eerie beings, the carriers of the curse.

One day in the inner land, one of the beings finds a human girl in a heap of undead bodies.

The girl says her name is Shiva and she calls the being who found her "Teacher."

This is a story of two people—one human, one inhuman—who linger in the hazy twilight that separates night from day.

[Source: Crunchyroll; emended]