A town called Norrisville has been protected by a ninja for 800 years. But what the citizens of Norrisville don't know is that a new ninja is selected every four years. Every ninja starts out as a freshman and when the ninja graduates they pass down the ninja suit. 9th grade teenager, Randy Cunningham, is the next ninja. Randy is bummed, however, that he can't tell anyone. So instead of telling his best friend, Howard, that he's the ninja, he comes to the school for a "meet and greet", not knowing that an evil sorcerer is planning to destroy the ninja.