Synonyms: Darker than Black: Ryuusei no Gemini Specials, Darker than BLACK 2 OVA, DTB
Japanese: Darker than BLACK -黒の契約者 外伝
Aired: Jan 27, 2010 to Jul 21, 2010
Genres: Action, Mystery, Sci-Fi, Super Power
Rating: R – 17+ (violence & profanity)
MAL: Darker than Black: Kuro no Keiyakusha Gaiden
Tells the story of what happened to Yin and Hei between the first and second series.