Gekijouban NARUTO: Shippuuden - The Lost Tower

Assigned on a mission to capture Mukade, a missing-nin, Naruto Uzumaki sets out for the once glorious historic ruins of "Ouran," where he pursues and corners the rogue ninja. Mukade's goal is revealed to be a dormant leyline within the ruins; he unleashes the power of the leyline, causing a light to envelop Naruto, sending him into the past, 20 years before the series began. When Naruto awakens, he comes into contact with the Fourth Hokage, Minato Namikaze.

(Source: Wikipedia)

A ninja was a covert agent or mercenary of feudal Japan specializing in unorthodox arts of war.

The functions of the ninja included espionage, sabotage, infiltration, and assassination, as well as open combat in certain situations.
The ninja, using covert methods of waging war, were contrasted with the samurai, who had strict rules about honor and combat.

Ninja

Action anime usually involve a fairly straightforward story of good guys versus bad guys, where most disputes are resolved by using physical force. It often contains a lot of shooting, explosions and fighting.

Action

Adventures are exciting stories, with new experiences or exotic locales. Adventures are designed to provide an action-filled, energetic experience for the viewer. Rather than the predominant emphasis on violence and fighting that is found in pure action anime, however, the viewer of adventures can live vicariously through the travels, conquests, explorations, creation of empires, struggles and situations that confront the main characters, actual historical figures or protagonists. Under the category of adventures, we can include traditional swashbucklers, serialized films, and historical spectacles, searches or expeditions for lost continents, "jungle" and "desert" epics, treasure hunts and quests, disaster films, and heroic journeys or searches for the unknown. Adventure films are often, but not always, set in an historical period, and may include adapted stories of historical or literary adventure heroes, kings, battles, rebellion, or piracy.