Naruto S2004E12 - 月夜の暗殺者

When Naruto sees Gara he decides to flee, but Gara is too fast and tries to kill Sasuke. Sakura protects him which stops Gara as he finds himself tormented again by seeing someone risking their life to protect another. Through flashback we see more of Gara as a child and how meanness of others turned him toward the path of darkness and hatred.