The 21-year-old Kagura Shino plays the role of a ninja in the ninja village's Ninja Show. In her spare time she engrosses herself in Sengoku Online, a game based on the Warring States period of Japan, and is quite the historical play otaku.
One day, the two worlds collide and Shino finds herself transported into the world of Falyias where she is forced into the role of a pressure valve for the mana exchange between the two worlds.
As a form of apology, the world's caretaker allows her to inherit all the powers of the character she played in Sengoku Online. With power that even the Demon King couldn't scoff at, Shino begins to live her life in another world.