User blog comment:Mnzombie/Issei's Peerage/@comment-174.119.241.202-20131027012031/@comment-9339850-20131027012537

Well first of all, Issei isnt engaged to Rias on any condition, they are engaged because they love each other and Rias' family have basically already accepted him into their family as well. Becoming High-Class would come naturally because Issei wants to have his own Harem team (he wont but thats a whole other story)