3 Ninjas

Every summer, the Douglas brothers, Samuel, Jeffrey, and Michael, visit their Japanese grandfather, Mori Tanaka, at his cabin. Mori trains his grandsons in the art of ninjutsu. As the summer comes to an end, Mori bestows on each of them a new "ninja" name based on their personalities: Samuel being 'Rocky', Jeffrey being 'Colt', and Michael being 'Tum-Tum'. The boys' father, Sam Douglas, is an FBI agent who stages a sting operation to entrap a master criminal named Hugo Snyder in the sale of warheads. Snyder evades the trap with his ninja henchmen, flees by helicopter, and later visits Mori, his former business partner. Mori is tested by Snyder's ninjas and defeats them with his grandsons' help. Face to face, Snyder fails to persuade Mori to train his men and threatens Mori's family if he does not tell Sam, his son-in-law, to cease pursuing him. When the boys return home, they find their father unenthusiastic about what they learned during their visit and more annoyed by their new names.