Duellwalzer OVA / Detective Kun Kun consists of only one episode, and is found on the Rozen Maiden: Duellwalzer PlayStation 2 game disc. The show is presented as an opera performance with curtains, showtime buzzer and stage. The story is about how Detective Kunkun foils the evil cat's plans to steal a beautiful gem from another character. This episode portrays watching Detective Kunkun's show from a Rozen Maiden doll's perspective.