So form what I’ve seen it’s because idk I think in the first few chaps the ml girl she sees things like bugs so in one chapter it was her when she was a kid and saw I think a caterpillar bitting a leaf and she kills it with a rock cause she didn’t like it and now the ml the guy he seen people who he disliked as a caterpillar and he will kill them no matter what but it’s still hard to know why he obsessed but my opinion is that’s he sees how they both see things the same and that’s how he’s obsessed with her and weird thing his victim the girls have the same hair color like the ml girl but I doubt he kill her after seeing her kill the pervert uncle he fell hard.
Hmm I think it’s because he views her as “some thing he wants”/ “wants to protect or have”. Like those little trinkets he collects. For example the watch, and the pen. I wouldn’t say he views her as an object though. Maybe in his own way that’s him liking her. It’s kinda hard to put into words at the moment, but that’s what I got from the story so far.
She shines, to him. Every object he’s coveted and possessed shone in his eyes. That’s the only way he explains it probably because that’s literally all there is to it. He said once that she looks like she should break but doesn’t. So that might also be a factor. Can’t find the correlation with the other objects he has though because they each were important to the person he killed.

Again why he obsessed her ? I was about read this saw on tiktok