Birdy the Mighty: Decode Season 2 Episode 6 A Prisoner of the Past ( Air Date 2009-02-14 ) Genre Animation, Action & Adventure, Sci-Fi & Fantasy, Comedy category. Overview "In an attempt to reverse the personality merging process, Tsutomu delves into Birdy's past. In this episode, he learns what it means to be an Iksiola, and how Birdy met Nataru.".