Who are You?!

Unable to find a pulse on Zabuza, Kakashi decides the masked youth has finished him off. Taking the boy for a Mist hunter-nin, he lets the stranger act freely, telling his students that such operatives exist to hunt down and erase rogues like Zabuza. Naruto bristles at how someone so young could bring down so fearsome an opponent, but Kakashi warns him this is a reality he must learn to accept.

Once the boy departs carrying Zabuza's body, Kakashi's strength gives out, drained by his heavy use of the Sharingan, and he is carried to Tazuna's house to recover. He later wakes ringed by the genin, Tazuna, and Tazuna's daughter Tsunami, estimating that roughly a week will restore him. Sakura asks about the masked figure.

Kakashi explains that hunter-nin belong to the Anbu, the most elite and secretive force of the Hidden Mist. A shinobi's remains, he notes, hold a village's secrets, from ninjutsu and chakra to medicines and prized kekkei genkai like the Sharingan, so hunter-nin destroy rogues and dispose of their bodies without a trace. Meanwhile, the boy revives Zabuza, having only feigned the kill to rescue him from Kakashi.

Kakashi mistakes Haku for a genuine hunter-nin and allows him to take Zabuza. Overuse of the Sharingan leaves Kakashi bedridden at Tazuna's home. He teaches the team about hunter-nin and why a corpse endangers a village's secrets. The masked boy secretly revives Zabuza.

Set in the Prologue: Land of Waves arc and gathered in volume 2, the chapter introduces the concept of hunter-nin and plants the twist that Zabuza survives his apparent death.