User blog comment:B214/Question & Answers 5/@comment-71.120.219.7-20160513185727/@comment-26345952-20160513195552

well he did try to cram in 3 volumes in 12 episodes. Usually, DxD's form is 2 volumes per season (without counting any short stories). So he tried to re-write vol.s 5, 6, and 7 in a new flow. Thus appeared what we all knoow as BorN.