User blog comment:B214/Talk About What You Want! 3/@comment-3965848-20150408202841/@comment-1359322-20150409070754

Season 1 didn't have the split arc like Season 2. Yes it was 2 volumes like Season 2, but unlike Season 2 which TNK has explicitly divided the arcs, Season 1 didn't have those. You can even say the reason why High School DxD New has 2 openings and endings.



They even specifically show it in the logo for Season 2. That's why Season 2 has a split arc while Season 1 doesn't have one.