Double Down Kangurou (ダブルダウン勘繰郎, Daburu Daun Kangurō) is the first novel of the JDC Tribute Series, written by Nisio Isin and illustrated by George Asakura. It was released on March 6, 2003[1], with an omnibus version, also containing Triple Play Sukeakurou, released on January 15, 2010[2].
Based on the JDC Series by Ryusui Seiryoin, it is a part of the JDC Tribute Series. Aside from the two novels written by Nisio Isin, the tribute series also contains Tsukumojuku by Otaro Maijo and the Tantei Gishiki manga series by Eiji Otsuka and Chizu Hashii.