The 19th century — a world inhabited by vampires, golems, werewolves and other paranormal creatures. Immortal beauty and disembodied head Aya Rindo, along with half-human-half-demon "Demon Killer" Tsugaru Shunichi and her loyal maid Shizuku Hasei, travels through Europe as supernatural detective "The Cage User," solving supernatural mysteries while she searches for her lost body.