User blog comment:B214/High School DxD DX.4 discussion/@comment-200.86.86.39-20170719231524/@comment-26345952-20170720023942

But isn't this Dx volume in particular considered as an extension of Vol. 23 of the main story? A 23.5 so to say. I think this is the only one that is considered a part of the main story.

Which remainds me that even in the main story there are things that are recalled from the short stories (be a Dx volume or one published seperately) so basically aren't some short stories needed to be considered parts of the main story?