Description

On a winter day, my younger sister's body plummeted into the courtyard of Kagome Seishin Girls Academy.

A sanctuary to young girls, a paradise for lambs.
Like this place, my sister closed herself off from the world
long ago, drifting in space until gravity brought her down.

She escaped with her life intact, but fell into a coma.

And now I, Tooku Houmuku,
and my friend Shizuku Mizuumi,
are looking for the reason that my sister fell --

(edited from DLSite English)