Inspiration for the story came from works including Shūzō Oshimi's Inside Mari, Ranma ½, the Heian period novel Torikaebaya Monogatari, and Greg Egan's short story The Safe-Deposit Box [REF].
While the town of Itomori, one of the film's settings, is fictional, the film drew inspirations from real-life locations that provided backdrop for the town.