Mitsuki Aya enters one of the best all-girl schools in Japan. One day, she sees a fellow classmate enthusiastically playing a fighting game in an empty classroom. Forbidden from playing games at the school, Aya, who is also a secret gamer, wants to play against her!

Aya transferred into Kuromi Girls Academy a month ago with the goal of changing herself into a proper lady. After meeting the breathtaking Shirayuri, Aya is blown away by her elegance and posterity. Imagine her surprise when she finds Shirayuri after school playing... a fighting game?! And if that wasn't perplexing enough, she is challenged to a duel by the unladylike Shirayuri!