After the manga/comic became popular Fuminori Kizaki and the renowned studio GONZO (Basilisk, Samurai 7, GANTZ) created a 5 episode long Anime. Funimation, responsible for the publishing in North Amerika, decided to relase two versions on DVD. One was the normal TV version, as it aired on Spike TV (or Fuji Television in Japan), but there was also the Director's Cut version. This version isn't only longer than the normal version, there was also a change of voices.