Together with his friends Carly, Matt, and Umberto, Derek has fun learning about all the cool aspects of ninja culture. When someone starts vandalising their school with graffiti of a mischievous troll-like figure, these ninjas-in-training are convinced they'll be able to crack the case. But it turns out that being a ninja is a lot more work than they thought, and this adventure brings about new opportunities for Derek to embarrass himself. For once, can he be the hero that saves the day?