You're doing too much work for this comic.
The stuff you said about chizuru is all nominally true or at least gestured at, but the biggest reason I find this comic frustrating is because it seems to want me to be invested in the way she feels while also being very unwilling to demonstrate the way she feels. It's so determined to make sure she seems like an unattainable prize that the protagonist is unworthy of that it doesn't really allow her any inferiority. We're like 300 chapters in and she's only recently started giving any indication that her feelings towards him are starting to thaw at all.
When I complain about how anxious the comic feels, it's not because I find it unbelievable, it's because I think it's bad storytelling. For the pages and pages and pages it spends on kazuyas internal monolgue about how he's a sad little failboy and how chizuru hates his stupid guts, it doesn't even seem conscious of the fact that that's a negative trait he has. It's just, like, his charm point. His anxiety isn't something he's aware of and is working to overcome, it's just something that's there because this girl is like a precious stone that he would like to have sex with and he's a fucked up little man who doesn't deserve to look at her, and that's something that we need 5-8 pages of every chapter instead of anything at all happening.
It's fine to make a comic where the protagonist is anxious or is dating someone out of their league and thinks it's too good to be true, but ideally you would write about those things with a goal in mind, not just because you think it's an entertaining thing to make me read for 6 years.