White Past: Hidden Ambition

The Nine-Tails chakra recedes after Naruto used to attack Haku while dispelling his mirrors, breaking his opponent's mask and revealing him as the youth he previously conversed with. Asking Naruto to kill him as he had failed Zabuza, a flashback reveals that he had inherited his ability from his mother as they lived in the Land of Water. But as those with Kekkei Genkai are demonized, Haku is forced to watch his mother murdered by his father before subconsciously invoking his powers to kill his father and the angry mob. Some time after, Haku was found by Zabuza and trained to hone his skills to be of use to the swordsman. Meanwhile, having sensed Naruto only released a fraction of the Nine-Tails' chakra, Kakashi summons a number of dogs to find and restrain Zabuza. At that time, Haku manages to convince Naruto to kill him before seeing Kakashi about to finish Zabuza off with his Lightning Blade Technique.