The Cost of Betrayal Gettobakkâzu dakkanya : Season 1 Episode 42

The "Paul's past" episode. We discover that Paul used to be a negotiator and info man for a three-person team of thieves-for-hire. However, one of his group turned betrayer, and after that he retired from the thieving world. When his other partner comes back with new data on the whereabouts of the betrayer, Paul brings Ban and Ginji on a mission to recover what was stolen from him long ago.