You say cartoonishly villainous i say just slighty unrealistic a lot of people are way worse, i know of multiple people who suffered way worse than just violent beatings (not to downplay it).
You might just be used (not trying to insult you) to manga were everyone talk together, they shout loudly maybe some punches are exchanged and everything is solved and the day after we act like nothing happened because we dont want to bring "shame to the family". Japan is kinda of a fucked up country when it comes to this kind of issues where a person needs exterior help to get protected.
It happened about 20 years ago or more, primary school student ran away from home and spent few days wandering around the city, it happened twice.
There weren't any signs of mistreatment, neither was social or talkative. No bullying, grades were fine.
Family ran a garment accessories shop and was living well enough to be mid-high class. City was well known for its textile products.
After 2nd escape, frew weeks later was found in the enclosed forest reserve within city limits.
After graduating and going to university, while driving through old neighborhood, found their luxury house in total mess. Asked around just to found out her parents broke up, father was accused of DA and attempted murder on wife few years ago...
Not trying to pin a tail, might develop his misbehaviour after tragic loss of his daughter,
but...