User blog comment:B214/Question and Answers 2/@comment-96.255.45.78-20140522022705/@comment-42.117.110.207-20140522031159

That would happen if High school DxD is a Visual Novel or a seinen Light Novel, the publisher can't go far because that would drop the sell of the Light Novel which is making them money, at least we can still wait for the last volume (instead of getting confess, kiss, one girl only we get a Issei being matured with his harem.)