Definitely head over heels in love, like the boy is definitely obsessed when he gets a crush on you. And he wouldn’t even realize it either. He’d think that he liked you a normal amount and that all his feelings were completely normal and justified. I mean it’s just a crush, right? That’s totally normal.
Naruto would want to know all about you. What you like, what you dislike, your favorite things, everything. Every detail about you is just so interesting, he needs to know it all! And perhaps you’d even like him better if he knew all about you!
He’d be pretty delusional about his feelings, of course. Naruto has no idea that there could be anything wrong with the way he acts towards you or the feelings that he has. He just has a crush, okay? There’s nothing wrong with that and no one would be able to convince him otherwise because he is just so confident in this way of thinking.
A very love sick boy. He’d be totally star struck by you. You swear you can almost see the heart shape in his eyes when he looks at you. You’re just so amazing and pretty and cool! How could he not be completely and totally in love with you? You’re just too amazing for him not to be.
Naruto would cling to your side like glue 24/7 whenever he had the opportunity. He would be extremely clingy and would follow you around like a lost puppy. In his mind, you two are 100% totally in love so you should obviously be spending all of your time together because that’s just completely logical.
In his mind, anytime you two hang out together that’s a date. Oh, you’re going to go out to lunch? Well you should definitely go with him to Ichiraku’s.(by the way, this is definitely a date because you two are going somewhere together.) Anytime you’re going anywhere, Naruto wants to go too. And that therefore means it’s a date because you two are going together as a couple. Even if you aren’t a couple at this time and have no idea it’s a ‘date.’
He’d realize at some point that you probably don’t interpret everything the way that he does and that you haven’t been on as many dates together as he thought you two had. But he nonetheless assumes that there is still a romantic undertone to your relationship and that you’re just too shy to make it official with him. But that’s okay, he understands! He’ll just ask you to be his s/o instead.
Even if you reject him, he won’t give it up. Even you say to his face that you don’t like him or something, he’ll just warp it in his mind to mean something else. He just has to keep trying! I think he’d also be pretty desperate so he definitely wouldn’t give up on you. Or in a scenario where you two were together but you wanted to break up, he wouldn’t accept this easily. He needs you! Everyone else in the village has rejected him before but he can’t accept that from you! Please please love him!
If you rejected him or didn’t pay attention to him enough, he’d act out towards you so you’d notice him. It didn’t matter if his antics made you mad or dislike him, you paying attention to him negatively was better than no attention at all.
I also think he’d be really overprotective, no matter what your relationship is with him. It’d be his number one priority to keep you safe. It’s just so dangerous out there especially with the Akatsuki out there. He’d go out of his way to try to protect you no matter if you were a normal civilian or a capable ninja.