"The day I received magic was also the day of my death."

Watanuki Sakuya wakes up in an old shrine, only to find the corpse of a girl hanging before her, flowers blooming out of every part of her corpse. She was meant to have visited the village with her best friend, and yet, what could've occured to lead to such a thing...?

Nine other girls are at the shrine. All of the surviving girls also have flowers blooming from one eye. A girl called Yumemi appears, claiming to the one in-charge, and explains the situation;

"—You are all magical girls, chosen for the sake of the Kamibana."

Every evening, at 8 p.m., during the Hanamukenogi ceremony; a girl is chosen to be offered to the sacred flower and hanged.

[Translated from Official Site]