It is easy to send an OLD (pre-1977) vehicle TO Japan. Anything newer is very, very difficult, as their emissions standards are MORE stringent than the US or Canada are. What is the vehicle titled as? Is it the frame donor or the body, and which numbers are on the registration docs? Since you are in Japan, it's gonna be far easier to get with a Japanese agent and have him help work the issues for you. He's gonna know the rules for bringing a vehicle into the country.

Pessimist - Sees glass as half-empty. Optimist - Sees glass as half-full. Gov't- Sees glass and takes it from you because you have a glass.
Political Correctness: A philosophical belief system bereft of common sense and logic, that supports and rewards ignorance and stupidity.