Aka no 9-ban Reiju

is a Japanese light novel series written by Akira Aihara, with illustrations by Kazuoki. The series began publication on January 10, 2010 by ASCII Media Works under their Dengeki Bunko publishing imprint.

Synopsis
Tsukushi Kinoshita, a dull high school boy, finds a blog that his classmates think he wrote while wandering around the internet one day.

"I'm Red No. 9'Slave'. I'm looking for a player to bet on me as soon as possible." ──Kazu Oda, a classmate who has a dignified attitude and many fans of the same sex, is actually a game. It was my favorite comrade (this may be a chance) !?

When I talked to her with such a delusion, I couldn't help but notice her strangely destined appearance, and when I noticed, as her servant, "The fate of the earth" To get caught up in the "fate game" betting "── !?