3 Ninjas Kick Back

The three titular ninjas of the story, 12-year-old "Rocky," 11-year-old "Colt," and 7-year-old "Tum-Tum" are brothers experiencing the pressures of growing up. They frequently spend time training in the ninja arts with their grandfather, Mori Shintaro (Mori Tanaka in the previous film). Mori plans a trip for the four of them to Japan to take them to a martial arts tournament of which he was the champion fifty years ago. Only Tum-Tum seems interested in going, and even then, only out of interest in seeing sumo wrestlers due to how much food they get to eat. Mori tells the boys he hopes to return a dagger awarded to him at the tournament when he defeated a boy named Koga, so that it may be presented to the new winner. In Japan, a man later revealed to be Koga breaks into a museum and steals a sword before escaping via hang glider. At a baseball game, Rocky seems too focused on a cute girl to pitch properly, Tum-Tum causes constant breaks due to getting snacks, and Colt's temper causes a fight with the opposing team that causes the umpire to call off the game until the next week, driving a nail into the boys' plans to travel.