Ryoko Mitsurugi is a high-school girl who intends to be a samurai. In her high school, there is a system named "K fights". It is a system which solves all the troubles by the duel of the school official recognition. And, Ryoko is a present champion of the K fights. The person who challenges to defeat Ryoko is unfailing, and her school life is a fuss every day. One day, Ryoko obtains a mysterious pendant. And, she was somehow in the another world after the pendant shoots light. There was a shrine maiden named Reiha in this world named "Solvania Shadow". She calls Ryoko the ogre of Yenen. And, she says the work of Ryoko is to defeat the monster of this world by her.