User blog comment:B214/Volume 23 discussion blog/@comment-31137559-20170325201002/@comment-9595671-20170326025500

It is part harem series, fans will always want a certain girl in the harem, but sometimes only fanfics will make it happen. For some like Gabriel and Serafall they're believable, though the chances are known only to Ishibami.

I think the reason behind this is some fans think that they'll get a girl in if enough of them want a certain girl in the harem, cause I think I heard once the fans got Ishibumi to add Kuroka into it because she was well liked, so they're hoping to repeat it I guess?