Ran is a personification of the "sandwich generation." That part of the middle class of modern day Japan that are caught raising their children and caring for their parents at the same time. A lot of 60something Japanes retirees, freed from the responsibilities of raising kids and going to work 50+ hours a week regress into a kind of adolecescent behavior. They sleep a lot, drink too much, spend too much money, and won't do house work, but continue to demand "respect" from their kids. Exactly like Yukari. Meenwhile there are also actual kids in the house that the parents are trying to discipline but the grandparents are lying around, or getting into trouble, providing bad examples if not outright enabiling the kids or spoling them with gifts (Yukari and Chen). Meanwhile the current working generation gets stuck with the bills, and the legal problems of both their parents and kids bad behavior.