A very ancient monster, Okamuro San, appears to those who say his name or search for him on the internet to chop off their heads...

The film depicts a coming-of-age story centered on the two sugar babies, Kotone, who is unemployed, and Sakura, a college student, in the coronavirus pandemic, as they try their best to live at the mercy of frivolous men.

YouTuber Tomoki Uchikawa, along with his friends Hinako, Souta, and Nanae, head to the former Ishio Village, where there are rumors of people being spirited away, to film a video investigating urban legends. However, their whereabouts remain unknown, and the police discover the rental car they had rented near a tunnel on the outskirts of the village. The video cameras left behind there show shocking images of locked houses, children in armed uniforms, imprisoned adults, and adults being infected by a strange disease, a rotten demon, that occurs on the night of a new moon.