Living a troubled home-life, a teenager becomes so stressed out with everything around her that she disappears into a series of fantasy-related books. While trying to escape her situation, she soon finds herself living in feudal Japan with a ninja master and his students who inform her that she's in a separate dimension from her regular life and are to help train together in the way of the ninja. When the training's complete, the girls learn that an evil warlord that left them orphans has intentions on killing them all as well, forcing the girls to team up together with all their training to defeat the madman and live in peace again.

부모님의 잦은 다툼과 친구들의 따돌림으로 괴로운 여고생 '마코'. 마음 기댈 곳 하나 없이 외로운 그녀에게 유일한 즐거움은 멋진 닌자 소녀들이 나오는 그림책을 읽는 것이다. 그러던 어느 날, 점점 심해지는 따돌림으로 지친 ‘마코’ 앞에 그림책에 등장했던 닌자 소녀 '유우'와 '히로'가 나타난다. 그렇게 두 사람은 마코를 다른 차원의 시공간으로 데려가는데…