Kazuki Tsukigase transfers to a high school on a remote island to avoid people who know him. He discovers an inlet where locals report disappearances. While exploring, he finds an unconscious girl, later identified as Nao, 16, who awakens at a clinic and says only her name, age, and the year 1974. The film, directed by Junichi Wada and written by Sayaka Kuwamura, is based on a novel by Akiko Abe. It follows Kazuki, a pianist who abandoned his talent after an incident, and Nao, a girl who appears to be from 1974 and becomes his companion. Supporting characters include Nao’s adoptive uncle Takatsu and Kazuki’s dormitory peers. Production credits list Kōji Nakamura as music composer and Hechima as character and chief animation director. The film received a C overall grade and a D+ story rating.