Good girl, bad boy. He thinks she’s cute but doesn’t consider himself to be good enough to actually go for anything with her. Though, since she’s described as not being stuck up at all despite her status, there’s no way she would consider him beneath her.
Also, in the Norwegian translation of the book (which I generally just assume is more faithful to the Original because of how they don’t have every character refer to each other with their first name, instead using the first/last names properly depending on friendships etc, but this isnt the point), when he sees her body and asks Kiriyama about her, he does this little stutter and is very obviously shaken to see her dead. I always assumed that despite him saying he wasn’t “stupid enough to have a crush on her,” he might have actually been just that.