Yuuma had his future all planned out: he would join the literature club, fall in love with his senpai, and become a best-selling light novel writer. However, it all came apart when his homeroom teacher informed him that the literature club had been disbanded many years ago. He couldn’t find another club where he would be able to write novels, so he ended up finding a nice place in the library to focus on his writing. Then, he was forcefully recruited to the student council as the secretary, mainly to take care of the mounds of paperwork which had piled up.
After some incident, he ended up as a member of the second literature club, which was actually the occult club and the Grimoire ended up in his hands. According to club leader Yuzuna, if one makes a contract with the book, then they will become popular with the opposite sex. She was really eager to try it, and he became her test subject. However, it actually possessed magic which made others sexually excited, causing all types of ecchi events to occur around him!