Short-Term Visit
USA
You will not need a visa for a period of stay up to 90 days.
This visa exemption is not applicable for stays exceeding 90 days, or for stays involving paid activities, journalistic activities or attending depositions.
Please have a valid US passport, and a return/thru ticket available at the port of entry in order to show that you plan to leave within 90 days.
As a general rule, "visa free" entry status may not be changed to other visa status without departing and then re-entering Japan with the appropriate visa such as a spouse, work or study visa.
This is what it said on the Japanese Embassy website. Does this mean if you can obtain a passport you can just catch a flight? Can you get a passport with a felony on your record?