Assassin of the Moonlit Night

is episode 76 of the original Naruto anime.

Synopsis
Seeing Naruto and Sakura's determination to protect Sasuke, Gaara remembers his childhood with his uncle Yashamaru. They talked about pain — with Yashamaru explaining to him that the pain dealt to the heart takes the longest to heal; the only medicine being love. Gaara, in time made a deep bond with him feeling the pain going away with Yashamaru's love. One night, after he killed a drunk, while Gaara was lost in deep thoughts, an assassin attacked him from behind. Gaara's sand protected him as always and he attacked the assassin. When Gaara went on to check the person behind the mask, he was shocked to see it was Yashamaru.

El asesino de la noche de luna