After their brutal battle in Vol. 2, Kakashi sets the trio a stern task designed to strengthen their chakras and develop their ninja powers. Naruto, the weakest of the three, shows his strength of will as he struggles day and night to best Sasuke's accomplishments. This single-minded focus develop's Naruto's character as much as his chakras, as he slowly hardens and changes from the selfish blowhard of the first volumes. Along with this, he develops a relationship with a small boy from town, Inari, who learns what it means to be a hero.
While this self-development is all good and well, the real story begins when Zabuza and Haku attack again, facing off against the stronger, re-grouped trio. However, the demon and his companion have been training as well, and Zabuza has learned the secret of Kakashi's "Sharingan Eye," and how to defeat it. Haku has secrets of his own, and Naruto and Sasuke are powerless against him.
