Gakkō no Kaidan(学校の階段, lit. The School's Staircase) is a Japanese light novel series by Takaaki Kaima with illustrations by Amane Amahuku. The first novel in the series was released on January 30, 2006, and as of October 30, 2008, nine volumes have been published by Enterbrain under their Famitsu Bunko publishing imprint. A live action movie adaptation was directed by Hirosaka Sasaki and premiered in Japanese theaters on June 9, 2007. The word kaidan used in the title is homophonic to the word kaidan(怪談), meaning "ghost stories".