
that he's totally wrong for her? Whether he's married or not is such a tiny issue compared to the fact he's about 30 years older and a yakuza boss. No one in his position is expected to be "good" and having affairs with cabaret girls is like...lol, duh.
Maybe you've been spoiled by too many romances with yakuza where they turn out to be misunderstood romantics who change into upstanding citizens because of love. This ain't that kind of story.
Does he care about her? Probably, yes, in his own way. He's touched by her innocence, intrigued by her fascination for him (which is clearly real and not an act put un by a cabaret girl), and there is the obvious, "I could totally make her mine," temptation that has to be lurking in the back of his head. He isn't lying to her though, or pretending to be a better man than he really is.
He kind of likes her, he might eventually have sex with her, and at some point, she'll face the fact that it's all wrong and cry and have a broken heart and move on with her life - a little wiser, hopefully.

Not every character is obsessed with him, mostly just the MC since every other character works for him (or the MCs best friend who's kind of... "Eh, not my type but whatever. Just be careful." He's yakuza boss - he's wealthy, he's powerful, he has an air of self-confidence and strength. And while he looks scary, he isn't mean (at least not to the average person. I'm sure he'd waste no time getting rid of an enemy).
Some people are drawn to that sort of person, either imagining/hoping the confidence will rub off onto them or they will be protected and cared for or they can use his power to their advantage. And there's an associated power trip with having that sort of person fall in love with you - "Wow, I must be really special to make such an amazing person love little old boring me."

I started reading this story knowing exactly what I was getting into - it's right there in the description.
So...what were all of you thinking who are complaining about everything? Teen girl is fucking her step-dad...that's the plot. Of course, they're all messed up in head. Mom's in denial/trying to fix it with extreme idiocy, Step-dad is a pig, College Boy liked her but also now can't respect her, Ayame is a confused, emotional disaster...yup. Sounds about right.
More body guard story! I like this one, aside from Haruma thinking he's causing all the problems - boy, stop that already!