Vist visa to SOFA

I'm on a vist visa. Can I move to a SOFA and stay in japan without leaving?

Are you in the military and staying on a base? From my understanding, the military will usually issue that status to you. Otherwise, I'd contact immigration and ask them or go to the embassy of your country within Japan and ask them.

As Tom mentioned, SOFA status is something issued by the U.S. government, so you'll need to speak with a U.S. government office, either at the U.S. embassy or a U.S. military base, about the process to obtain it. Basically, once you have SOFA status you're allowed, by the Japanese government, to live within Japan's borders, but the process of obtaining SOFA status is administered by the U.S. government.

Since you say you are on a visitor visa, I'm assuming that you are either looking to get a government job on a U.S. military base, in which case your potential on-base employer would be the first person to ask, or that you're planning to marry someone who already has SOFA status, in which case your future spouse would be the first person to discuss the issue with (as they should have access to the necessary legal advice on base).

I'm not aware of any requirement that someone be outside Japan while their SOFA status paperwork is being processed, but at the same time, I'm not aware of the Japanese government granting special permission to foreigners whose visitor visa has expired to remain in Japan while their SOFA status is processed. Because of that, I'd recommend you discuss the matter with your future employer/spouse as soon as possible.