A few years have passed since the end of the war in Showa-era Japan, and the season is summer. Hotaru, a war orphan, was taken in by the wealthy Hiiragi family, and lives a busy life every day taking care of the young ladies, Chizuru and Mio, and doing household chores. A series of serial kidnappings of schoolgirls has occurred, drawing public attention. Chizuru's classmate has also been missing for several days, becoming a topic of conversation. As summer vacation begins, the group, to pray for Chizuru's recovery from her illness, decides to visit Jishou-an, a temple lodging in the mountains. They are welcomed by a monk named Saiten, but Hotaru feels a sense of unease about the prayer rituals he performs. A familiar sutra, a skull, and Aizen Myo-o. Those stage props awaken memories of the past. In the midst of this, Chizuru, Mio, and Hotaru find a headless corpse in a mountain cabin, and the situation takes a sudden turn. A mother's love, a daughter's conflict, faith, and deception. If I stay here, I will be turned into a god or a Buddha―― [From the official website]