Both at the beginning and towards the end of the film, Shogo Kanetaka mentions a shrine to the goddess Diana where the priest is a killer. These are references to the shrine of the Golden Bough by Lake Nemi (just south of Rome). Supposedly there was a tree there one of whose boughs was golden. In Roman times, the shrine had a priest who assumed the position by killing the previous priest. The rationale for becoming the priest was that if the killer was a slave, he automatically was freed. This shrine was the initial inspiration for Sir James Frazer's massive book on mythology, "The Golden Bough". Note that "Golden Bough" appears as the name on one of the disused buildings in the film.