The song for the end credits is "Song of the Black Lizard" by Pink Martini, originally written and sung by Akihiro Miwa for the movie Kuro tokage (1962). The film is an adaptation of Yukio Mishima's play which is in turn based on Rampo Edogawa's noir novel, and Mishima wrote the play specifically for Miwa to play the lead. Although Miwa did not star in the 1962 version, he later played the titular role in Black Lizard (1968), another adaptation of the play directed by Kinji Fukasaku.
The movie is divided into three chapters: "World", "Devil" and "Flesh", the three enemies of the soul in Christianity.
The name of the girl Alicia was taken from Alice in Wonderland, and her father Luis was named after Lewis Carroll, as the director put it, Alice's "literary father".
Pedro Almodóvar wrote an article praising the work of Carlos Vermut, and it's rumoured he wants to produce his 3rd film.
At one point in the film Luis uses a search engine called "Rampo!", a reference to the Japanese author Rampo Edogawa.