Shaggy & Scooby are on the run! After Velma wins a contest for the best invention (a robotic dog) the gang gets to travel to Tokyo, Japan. When a mystical person zaps a pizza with a growing spell and Shaggy eats it! Shaggy starts to grow whenever he goes to sleep and he starts eating everything in sight. Now the gang are running around tokyo trying to get away from the police who want to put Shaggy in jail.