User blog comment:Ixarising/Favourite couple./@comment-101.113.19.26-20140823162519/@comment-1359322-20140826230831

The cover has nothing to do with the harem thing anymore. For starters, Ishibumi after the first two covers wanted the remaining cover to be all girls only and no guys, but since Volume 16 focuses on Gasper, so he agreed with Gasper being on the cover. Plus like i said, in his twitter, Ishibumi wrote that he originally wanted to add a romantic moment between Kiba and Tsubaki but was forced to scrapped off because of the plot.

P.S. Volume 13's cover is Akeno.