> I thought maybe difference between Westerner thinking rude to talk about money and Japanese talking about it openly, comes from whether your from country of Christianity or not.
> I read in a book that Christian society concidered commerce and financial business as negative things historically.

Good point, qchan. Yes, that's true. My mother often says "money is the root of all evil." I don't know if she got that saying from Christianity but it's a common sentiment around here.