The fate of a student thesis project was changed by the discovery of a long-lost 8mm film.
Deep in the Valley was conceived by Atsushi Funahashi as a thesis project for his students at ENBU Seminar, a film and acting school in Tokyo. In fall 2007, Funahashi taught scene studies to students in their late teens and early twenties, none of whom had any previous acting experience. At the end of the semester, Funahashi came up with the idea of introducing the students into downtown Yanaka and filming their interactions with the much older craftsmen of the neighborhood.
This documentary-style approach brought the production team a huge surprise when, during shooting, a long-lost 8mm Kodak Ektachrome film of the burning of Five-Story Pagoda in 1957 was discovered at one of the Yanaka temples. The film was made by Takao Shiota, a Buddhist monk of Myouohin Temple and the deputy president of the local fire brigade. Shiota had passed away, but his son had the film and showed it to the film crew. Inspired by this discovery, Funahashi decided to shift the focus of the thesis project to the mystery of Five-Story Pagoda.