Naruto and his friends get their first mission--to protect a man named Mr. Tazuna, a famous bridge builder; but Naruto also meets up with his first real enemy, Zabuza, the Demon of the Mist, who wants to make sure Naruto fails his mission.
As the evil Zabuza plans his attack, Naruto and his fellow junior ninjas attend an important training session where they learn about chakra, the energy needed to perform ninjutsu.