Wolf Guy" by Hirai/Kadota is an adaptation of three episodes of the "Adult Wolf Guy Series" novels entitled "Tsuki to Yoru to Oogami", "Oogami wa Shinazu" and "Jinrou, Akatsuki ni Shisu". *Note!! : The "'Wolf Guy Series" novels originate from the two volumes manga that are also entitled "Wolf Guy" (Hirai/Sakaguchi).