Credit rating doesn’t translate across countries. Even the US and Canada don’t share credit rating info (source: I’m a US citizen living in Canada and my credit history in Canada started from nothing), so the US and China definitely won’t. And banks are absolutely not giving favorable rates to students yet alone international students.
In fact if anything because international students get the worst tuition rates and few to no scholarships, then if OP’s story was real they would have spent minimum $20k a year just in tuition over four years, not even counting room and board. So if they did try to abscond with a more realistic credit card debt of like $10k they’d still be way underwater.
The only way this would maybe work is if they had a full ride scholarship, but only top schools like Stanford/Harvard give substantial scholarships to international students and at that point the student would be throwing away 4 years of a top top education for a relatively trivial amount of money, keeping in mind that again they’re never getting six figures in credit.
Meanwhile in Japan