Devil Box - Akumade Shimai!

is a Japanese light novel series written by Takashi Aoshima, with illustrations by Bakutendo. The series began publication on June 10, 2006 by ASCII Media Works under their Dengeki Bunko publishing imprint.

Synopsis
Just before going to elementary school, my mother passed away. Hikari became lonely for the rest of her life. Six eccentric and super-unique people who claim to be her sister appeared in front of her sorrowful. Hikari will live poorly and happily with her sisters. However, on her 13th birthday, suddenly her six older sisters disappear. Hikari feels lonely and feels depressed, but-!? A slightly H-like, fun and comical action story in which a girl who has a "devil" as her sister plays an active role.

It is a new sensation novel linked with the radio drama and mobile games in "Oji Hiroi's Maruten Mix". You can also get the devil that appears in the novel with a QR code.