Good points. There's another relevant one - in Japan, parents are liable if their child defaults on a debt. How much risk would you be will to take if you knew your parents might lose their house if you failed?
You know how you're supposed to return your rental modem by a certain date to avoid paying an extra fee? The person who previously rented my last apartment did not get her's returned by the date, so she owed the ISP $100. She also left the country prior to paying it. Lo and behold, when I tried to get coverage, they discovered the bill and asked me to pay it.
"I'm sorry, I think you have a misunderstanding. I am not this young Swedish lady."
"Are you related to her? Is she your wife, girlfriend, etc?"
"No."
"Quite the coincidence that two foreigners would end up renting the same apartment back to back."
"We're translators. Her contract is up, I'm replacing her, it is my employer's apartment."
"Oh. So that makes you coworkers?"
"Well, in a manner of speaking."
"You should pay to avoid causing embarrassment for your employer."
This is one of those times when my American brain goes "Oh hellllllllllllllll no" and my Japanese brain goes "Oh effity, you're right, that is what I am expected to do in this situation."
I paid.
If your adult child defaults on a loan, and someone knocks on your door (and there may be an actual physical knock and likely as not the person who is knocking is a yakuza enforcer, even if your adult child was in debt to an arm of a major publicly traded corporation), you pay. If your drunken useless excuse of a son has an automobile accident, you show up to the hospital several times with flowers and once with a discrete envelope with a generous amount of money to convey the depth of your sorrow for the lapse.
