Kabamaru is a young boy raised and trained by his grandfather as a ninja. After the sudden death of his grandfather, he starts living with Mai, his grandfather's mistress, who is a school director. He is asked to help out on struggles against other schools, as he is master of the ninja mystical arts. As time passes he will make lots of friends as well as enemies, and fall in love with Mai.

同名动画的电影真人版。
“The plot centers around a five part competition between Kabamaru representing Kin'gyoku School, and Hayate representing Ōgyoku School. The five events are falling from a height on a balloon (Kabamaru wins), swimming (Hayate wins), throwing shuriken while horseriding (Kabamaru wins), food eating contest (Hayate wins - Kabamaru is disqualified because he missed an olive) and remaining on the roof of a car driven by a student of the opponent school (Kabamaru wins after being promised 1,000 plates of yakisoba noodles by Shijune).”