Who I have the same questioned this topic

I'm going to Japan for about a month, and it seems that the best way to use my iPhone 4s is to have Verizon unlock it and then rent/buy a SIM card in Japan. I understand that this in effect gives me a local Japanese telephone number.

What happens if someone calls my regular Verizon US telephone number while the Japanese SIM card is active?  Does it go directly to Verizon voicemail or does the caller get a message like "this number is temporarily out of service"?

If calls to my US number do go to VM, how do I retrieve them?