This family is so scummy I can't believe God hasn't dropped meteors on them. It's cartoonish how much they suck. Often in this genre the scum gets a comeuppance. I wonder if this goes the schadenfreude route or if Aria leaves and never looks back?
Not as cartoonish as other mangas, where an entire blood-related family is just dedicated to persecuting the main character for no good reason.
Here we see that the father wasn't originally a noble, but married into a noble family. It appears that he caught the attention of the lady of the territory thanks to his martial achievements. He likely was forced to get some basic education, but it's not surprising if he's incompetent. We can see how the servants have little respect for him and the poor management of the house; he's likely getting scammed by merchants because all he cares about is fighting.
As for the stepmother and her daughter, their actions are perfectly aligned with their motives.
Also, I will add that as much as this manga is glazing over the main character's mother, she really made a terrible choice for her husband. It's strange because usually nobility will marry into nobility, so she should have gotten a match who had a certain level of education. Also, she apparently had no siblings nor parents, otherwise I would have expected them to protect the main character? Also, I know that margraves are fairly autonomous, but this country's royalty is definitely dropping the ball here because this territory needs a competent administrator yesterday.
Naive of you to think he isn't involved in the slave trade himself. Why do you think he was so quick to back off?
It's hard to say. From how he just took in a woman and her daughter, taking her word at face value that the girl was his daughter, and the general poor management within his mansion, I'd say he's not the type of person to scheme anything. He genuinely might be a moron who thinks the only way to maintain his current status is to chase achievements by defeating monsters and reporting on it. He might however actually be smart enough to realise he's being played, but have no idea how to resolve it; he seemed uninterested in his wife cheering him on.
He could still be involved, but more in the way that he's getting bribed to look away so that he can fund his current wife's absurd lifestyle.
So yeah, the father is currently the biggest mystery for me. I really do wonder how he's ended up being so apathetic. Perhaps he might have actually checked on his child if it had been a boy and he could have connected with them through fighting? How he's managed t neglect his daughter for so long is pretty wild.