The three-episode OVA Saiyuuki Gaiden is created by studio Anpro, based on a fantasy / adventure manga by Kazuya Minekura that serves as a prequel to the Saiyuuki series, by the same author. The story takes place in Heaven, 500 years before the first Saiyuuki series. The plot is based around that series' four main characters in their past lives, and details exactly what it was they did to get thrown out of heaven. The Japanese release dates for the OVA's three episodes are March 25, June 24 and September 22, 2011, respectively.