Courtesy of the IRS, there is a program now for Americans who have not been filing an income tax return while they have been working abroad (including Japan).
When I was in Japan and ever met a nonfiler, I always urged them to get their paperwork in order. In quite a few cases, they acted like I was talking out of my ass. But I used to say, that it was inevitable that the feds were going to catch up with them. Well, the first signal is there: the amnesty.
Come some future tax year, where the IRS goes asking for the tax return, the situation will be different. And as I’ve said, when the Service comes to you first, you lose the ability to exclude your foreign earned income.