The Karate School that Ethan attends is the same building used for the Cobra Kai in The Karate Kid (1985).
Was aired on Brazilian TV as third Il mio amico ninja (1993) movie. Film features same leading actor, same type of story and same producers.
In Ted Jan Roberts room you can see a poster on his wall of the canon film movie "Enter the Ninja" (1981).
Roberts played the lead roles in martial arts films such as Magic Kid (with Don "The Dragon" Wilson playing himself) and its sequel Magic Kid II, in Tiger Heart, "A Dangerous Place", and The Power Within.
Don Wilson and Art Camacho filmed with Ted Jan Roberts Magic Kid 1 and The Power within together.