Naruto Vol. 2 (manga)

The Worst Client

Naruto, Sasuke and Sakura have passed the final test to become junior ninja--but now the real challenge begins. Tired of menial tasks, the young ninja ask for a tougher assignment and find themselves--together with their teacher, Kakashi--bodyguarding a cranky old man from the Land of the Waves. But Tazuna the bridgebuilder is in more danger than anyone realizes: he's the target of elite ninja assassins, including Zabuza, "the demon," and our heroes are about to face a trial by fire...