In the midst of another dull and routine mission, Naruto finds himself in a battle with a mysterious knight, who possesses an even more mysterious power! Meanwhile, an invading army from across the sea gets into a fight with the Sand ninjas; but what is their motive? Naruto and the gang must now protect a wandering tribe who guard an ancient secret, engage in fast paced ninja action and keep up with their usual silly antics, ultimately leading to a dramatic conclusion where, once again, the old adage is proven true: "Never trust a man in a moving castle."
As London prepares for the first World Expo, the young Ray Steam receives a package containing the Steam Ball, a small and incredibly powerful engine containing hyper-pressurized steam. Developed by Ray’s father and grandfather in America under the supervision of (and funded by) the O’Hara Foundation, the Steam Ball could prove to be an asset to civilization or a great danger. But after Ray finds out that the Steam Ball must not fall into the O’Hara Foundation’s hands, he sets forth on a mission to keep the item safe and away from those who would use it to fuel a brutal war...
Steamboy and the second Naruto movie have decidedly steampunkish feels to them. Not so much in a traditional victorian way, but in the usage of various steam powered gadgets from moving castles to mechanical soldiers.
Their similarities also extend somewhat to their plots, where the main characters must protect a secret which could lead to ulimate power.