Fifty years ago, the master samurai fought in a ninja tournament to win a magical dagger that together with an ancient samurai sword, is believed to be the key to unlocking a secret cave laden with riches. After winning the tournament and rightfully gaining the dagger, it was stolen by the master's archrival, Koga. Though the master searched far and wide, he never found any trace of Koga or the dagger. Now, too old to continue searching, the master sends his three young apprentices, the young ninja brothers, Rocky, Colt, and Tum-Tum, to assist him in retrieving the prized dagger. Once it has been restored to its rightful owner, the dagger shall once again be passed along to younger generations, through the winners of the ninja tournament.