People in Japan because of the US military are on something called a SOFA visa. This visa is of course invalid if you are deserting but that is not the major is

People in Japan because of the US military are on something called a SOFA visa. This visa is of course invalid if you are deserting but that is not the major issue. For soldiers entering Japan they are not brought through Japanese immigration. Which means even if they had a passport they would not have the entry stamps. Thus any attempt to leave through immigration will only raise suspicions and get you handed over to the MPs.