--198X Minato Jinba, a university student, lives away from his parents in a boarding house in the city. One night, Minato receives distressing news from his father, Eiji. Minato's maternal grandmother, Kinu Miyama, is in critical condition. He embarks on a journey to Ichinose, a village deep in the mountains, where his mother was born. Minato had not seen his grandmother for over a decade and harbors a deep resentment towards her. She had refused to even attend her own daughter's funeral, further intensifying Minato's disdain. As the bus rumbles across the country road, Minato recalls his only conversation with his grandmother. "-- The thing with silkworms, you know; even if they could leave their cocoons, they have no mouths to eat, and their wings do not fly. They simply lay their eggs and perish." "People are the reason they suffer this fate." The sky reddens in the twilight, and the mountains cast an ominous shadow. Minato finds himself in this house There, he finds himself in a terrifying situation with a shocking truth.