User blog comment:SpookyBoogie27/Light Novel Spoilers/@comment-115.133.205.1-20130219144240/@comment-33447191-20130220042121

Yeah, honestly I'm not all that psyched about another Short-Story Volume so soon either. The truth is the author wanted to do a main story for Volume 15, but the publishers told him "No" and made it into a Short-Story Volume so they can bundle it with the Blu-Ray. And since Fujimi Shobo loves making money, they will most likely release a Short-Story Volume AGAIN next year.....

- (Info. from Code-Zero/n0m@n or Shin Code-Zero)