Naruto and Sasuke are bothThat is the worst thing Kishimoto introduced to the story at the 11th hour.reincarnations of the two dudes in the past. Those two dudes were always destined to fight each other. In this case, Naruto and Sasuke were bound for each other eventually, no matter the reason. Oh yeah, the two dudes were brothers. So in a way, Naruto and Sasuke are related, so it makes sense that Naruto would want to save him.