Haruja kot dojenčka najde skupina ninj in ga vzgaja v svojem duhu. Upajo, da je prav on tisti, ki naj bi po neki prerokbi prišel k njim in postal njihov vodja. Njihovo upanje pa z leti splahni in se spremeni v razočaranje, kajti Haru je daleč od tega, da bi bil bojevnik. Je debel, štorast, neumen in kjerkoli se pojavi, povzroči pravi kaos. Haru je sebi in drugim odločen dokazati, da je pravi bojevnik, zato na pomoč priskoči lepi Alison in se zaplete v nepozabno pustolovščino.
Following a ship wreck, a baby is rescued by a clan of Ninja warriors and raised by them as one of their own. But Haru, as he is called, never quite fits in, nor does he manage to make a worthy Ninja. However, the good-natured and persevering Haru, in his own bumbling way, and with some help from Gobei, manages to prove himself to be a winner in the end.