New York : Scholastic, c2012.
Translated from the Italian.
When Wild Willie showed up at my door and invited me to travel with him to Japan, I jumped at the chance. We were in search of an ancient, legendary samurai scroll that holds the secret to a long-lost fighting technique. The scroll had fallen into the wrong hands, and it was up to me and Wild Willie to track it down and save the day. But first, we would have to fight a group of talented ninjas. Holey cheese -- this would be one adventure I would never forget!