Laura and Sam, two private detectives who seem to have come straight out of a detective novel, want to follow a training course at Shuriken with the aim of improving their skills. They need to be able to arrest a gang of audacious thieves. The Principal lets them convince him with a thick bunch of bank notes that Laura offers him. However, it is out of the question that they be taught any secret ninja techniques, that must, as their name suggests, remain secret! Vlad immediately falls under the charm of the young detective. As for the students, they're captivated by Sam's stories!