Naruto being head over heals in love with Sakura throughout the whole manga, never wavering in his affection regardless of whether or not Sakura reciprocated his feelings or still loved Sasuke.
Sakura slowly but surely falling in love with Naruto despite his instance that he'll get Sasuke back for her (arguably, because she loves Sasuke and would have gotten together with him if Sasuke wasn't, you know, completely asexual/too in love with himself)
Also, Kushina telling Naruto that she wants him to end up with a girl like her and Minato confirming that Sakura is indeed just like Kushina