What is the catch with expat tenants?

[Pal Sa]

I have been getting some requests to show our rental to expats. It is usually a relocation agent that seems to be helping the client find a home. In my case, all of the expats seem to be from Japan. I have not verified but that is what the agents are telling me.  I find it strange that there are so many expats looking to rent a home in this location, all of them from one country, etc. 

Is there anything I need to be aware of? They won't have a credit history in the US or anything I can verify. Have you dealt with such situations?