Maybe this is where Arigatou differs from most manga of this ilk (the ones I've read, at least). Whereas in other series the patriarch's abuse would be presented in the most cliched way ever - through rape and impregnation of his daughters - here is the exact opposite. His overbearing love (represented in the manga through a heart literally brandished on his forehead) is shown through, quite physically, forcing all of the members of the family to stay together. Initially, he locks everyone in the house, later, he starts going to one of his daughter's school, to observe how others treat here. At one point, he even forces everyone to work together at a family restaurant.
Of course, it all has the exact opposite results of what the weak-but-willed patriarch expected. One of the daughters starts living with the boss of the gang that initially invaded her house and raped her sister. The mother joins a cult. The older sister becomes a hikikomori. And all this makes him even more overbearing and abusive, pointing, very weakly, though, to the evil that is the patriarchal system. Rinse and repeat with even more extreme examples until it all, very inorganically and anti-climatically, implodes.
There is a part in me that wants to read the manga as a consequence of the 1990's bubble burst coupled with the mangakas antiauthoritarian beliefs. The father never allows members of family to call the police or go to the hospital, or to have anything to do with any institutions. He hates all of them with passion and knows them to be corrupt, either trying to protect themselves and their image, or steal all of his hard earned money. He doesn't trust even his own company, and yet he abuses his position within it constantly. Until he is fired, that is, and even then uses the false authority he has over one of his colleagues. And if it was a critique of the post-bubble society, then what does this manga tells us? Well, not much, outside of the nihilistic surface level representation of contemporary society as broken beyond repair. Not that necessarily there needs to be a message, especially if there are compelling characters with novel or at least interesting arcs. But there are none here.
