The protagonist Ren's story continues as he adjusts to life as a devil in the peerage of Rias Gremory. In that he starts to get close to his fellow peerage member Koneko Tojou and the exiled nun Asia Argento. Both of whom, Ren was more than happy to guide into a new path of lust, debauchery and bimbofication.
Fox's Notes: I've taken the liberty to make some changes for Koneko and Asia. Both of them are the same age as Rias and Akeno in this story and some of their personalities may come of as a bit different than in canon.