Well, in some fanfictions, their friendship is shown as a slow - building trust. Naruto has always been eager to be friends with Sakura, but in these stories, Sakura gradually realizes how important Naruto is to her. For instance, when Naruto goes on a dangerous solo mission, Sakura starts to worry about him more than she expected, and that's when she truly begins to value their friendship.
Another representation is that they become best friends who are almost like siblings. They protect each other fiercely and are always there to back the other up. For example, if Sakura is being bullied by some villagers because of her association with Naruto (who was also bullied), Naruto would stand up for her without hesitation, and vice versa. Their friendship in this case is based on mutual respect and a shared history of being misunderstood.
The best chapter pointer here is Chapter 96, "Can't Easily Forgive the Scumbag!". It opens with Jiang Li's words seemed absurd, yet there also seemed to be a trace of... and closes on Xu Ling couldn't contain her soft sobbing, "How could this happen?.
Look to Chapter 87 for the clearest answer. It begins with Luckily, at that time, Jiang Li had already taken her pot of stinky..., keeps building through But all this still didn't escape the high-definition camera., and lands on I'm driven crazy by him every day.] [+1 from above!.
The best chapter pointer here is Chapter 85, "They must have been bought off by Jiang Li!". It opens with Facing everyone's skepticism and curiosity, Jiang Li explained fluently:... and closes on This fresh and vibrant flavor blended perfectly..
Look to Chapter 100 for the clearest answer. It begins with The barrage was about to die of laughter., keeps building through [Hahahaha, help, why is the young master always being chased!] [Next door,..., and lands on Her eyes flickered slightly as she grabbed the hand..
Chapter 111 is the strongest chapter-level answer because it starts from The main room's door was pushed open just a crack, and the head of the... and follows through on This time it was in a dream..
If you want the clearest chapter reference, go to Chapter 78. Early on, He Yun, too, tidied up and walked over to rest in the shade of a tree.; later, the chapter leans on After more than an hour of basking in the sun, his cheeks were....
A practical answer is Chapter 113, because it turns the idea into a concrete scene. The chapter opens with The next day, Jiang Lili was up before dawn as usual., adds pressure through Okay, keep them steady;
Chapter 81 is the strongest chapter-level answer because it starts from Qi Tianyu, who chose curry beef rice, received a piece of curry and a... and follows through on The summer on the Southwest Plateau is no joke; the sun at three o'clock....
Look to Chapter 87 for the clearest answer. It begins with Luckily, at that time, Jiang Li had already taken her pot of stinky..., keeps building through But all this still didn't escape the high-definition camera., and lands on I'm driven crazy by him every day.] [+1 from above!.
Look to Chapter 119 for the clearest answer. It begins with What is Princess Wen talking about?, keeps building through I can't understand a word?] [Is this some new meme?] [!!!, and lands on For some reason, he always felt there was a mysteriously calming power....