I know it’s too early to say this, but it seems like this guy’s wife set a trap for him. We’d better wait for the author to publish the rest of the work he just started.
As for the gyaru letting the guy live with her, it must be because of the hardships they both went through when they were kids.
In the flashback to when they were children, the girl has a bandage on her face and says she doesn’t want to go back home. It seems to me that the girl wasn’t being treated well—or at the very least, was being neglected by her relatives—and the protagonist insisted on staying with her all the time, even though he was punished by his parents when he came home late.
For the gyaru, the domestic violence accusation against the protagonist didn’t affect her opinion of him.