Joi Ito reminds us of something very important when doing business overseas - there are a lot of differences in business culture, and not all of the rule differences are formal - some of them are, and some of them aren't. This bit about transaction guaranties looks fairly formal:

I spent part of the day today in court. I was defending myself against the landlord of a friend of mine who has been unable to pay rent. I am the guarantor on the lease and the landlord has decided to come after me for the money. This is probably the fifth time that I've had debt collectors of various sorts come after me because of guarantees that I've made. I'm sure people wonder why the hell I keep guaranteeing things. The odd thing is that it is so common in Japan. It is as good as required for any significant transaction such as renting an apartment or borrowing money from a bank. Even government affiliated loans require personal guarantees by people other than the principles.

While this seems like an informal rule:

One of my portfolio companies failed several years ago. As the lead investor, I went around to the other investors and explained the situation. Two of the other investors asked me to PERSONALLY cover their loss. Both of these companies were public Japanese companies. I didn't pay of course, but they seemed to think that it would have been nifty if I had. I've never heard of such a thing happening in the US.

I'm not passing judgment (of any kind) on these practices - merely pointing out that they are an example of something that all international businesses need to be aware of. "Standard practice" may not be standard everywhere.