They are very different in many aspects,but being stupid is what connects their"bond".
Both Naruto and Sasuke admitted they felt like close friends.Hmmm no I don't think so hahaha.
Let's analyse Naruto and Sasuke in part 1:
For most of the time Naruto was in Sasuke's shadows only to shine in the fight with Gaara.They competed a lot,and not a single panel is with them showing some kindness or friendship.Sasuke was cold and distant with everyone,and with naruto he was also rude and arrogant lol,not even close to a friend.
Also Naruto never shared a friendship bond with Sasuke.He was always jealous of him and never wanted to listen to him.
And yet,after their time together in part 1,they call themselves friends without having a real friendship in the past.They even fought to the death,but as naruto said,it was a "fight between friends"
They were never friends,just stupid kids who only shared their experiences in their lonely life.