Watch Online Free on Watchseries. Norwegian Ninja is the true story of how Commander Arne Treholt and his Ninja Force saved Norway during the Cold War. In 1983 the Ninja Force discovers that the sinister NATO force Stay Behind, who take charge in times of war and emergency, are planning a coup-d'état in peacetime. Treholt and the Ninjas see only one solution: a full can of whoop-ass.