Arguably the development is all on Naruto’s side. Hinata loved him from the start, nothing has changed on her side. Naruto is slowly coming to the realization that she’s The One. Naruto, like Goku and many guys his age, is a little oblivious to romantic feelings.
Naruto’s stages roughly break down into:
"Hinata is a nice shy girl, but she’s a little weird".
"But people like you, I like"
To Neji: “You are going down” (as Hinata’s blood drips from his fist)
Hinata is the first person in Naruto’s entire life to tell him “I love you”. Naruto doesn’t know how to react, naturally. When she ‘died’ in front of him, he lost it. Through her sacrifice he unleashed the most terrifying power sealed within him.
He gripped his heart at the thought that she, and the other villagers, may be dead (by now she’s already very important to him, but she’s not yet THE special one.)
After Obito killed Neji, Hinata “snapped Naruto from his stupor” as my friend amitds phrased it. Chapter 614 is so important. After years of being inspired by Naruto’s determination, Hinata’s words are the ones to lift Naruto and change the course of the battle.
Twice Hinata managed to be this pivotal, with two of the biggest villains of the series. In the first case, Naruto lost control, in the second, he gained it through her. This is a mini-evolution in itself.
In 678 Naruto reacts to Hinata’s call alone, and he’s unaware of anyone else’s state. They’re connected already.
I like to think that actions speak louder than words, and Naruto is very kind and caring around her, just like she is toward him, he becomes increasingly so as the series progresses. Whether he’s aware of this or not, he has feelings for Hinata.
With his parting speech from Minato in 691, Naruto seems conscious of what he feels now. My hopes aren’t too high because Kishi has the tendency to have his characters recede before giving them development. However this close to the end, the last step to canonization is Naruto’s brain clicking into realizing he has feelings for her, and she’s the best partner he could ever ask for. They’re perfect for each other!
what about lack of development on Naruto’s side? Pllllease.