As far as I thought, he always wanted to improve their relationship despite him being frustated over her bratty attitude. At least for me, chapter 9, 15, and 16 indicating that he thought marriage with her is invetiable due to his father company and all. If you gonna marry her, why don't you at least improve the relationship rather than fighting daily over nothing.Is it just me, or is the writing for Koutaro inconsistent? Dude has been actively frustrated with the situation, tolerating it only for the sake of his family, since the beginning. However, he keeps wanting to do and be better... for her. There's been almost no moments of chemistry between them and no introspection from him to imply that he genuinely likes her in any way, much less a romantic way, so I feel like some steps have been skipped for him to arrive at this conclusion of wanting to do right by her.
She's not even close to being a piece of shit, she's just a little bratty and annoying. Calm downI don't even know what the author is trying for here aside from tits every panel. She's a piece of shit, but for some reason MC is gonna love her, even though he originally said it was just for the company, now he actually likes her even though she's done nothing but being a piece of shit.
Basically MC is a huge M. No other reason for him to actually fall for her other than he likes the abuse. She has no good points.