Where to file Japanese pension ?

You will enter your Japanese pension in the same spot you enter a Pension from a US based company.  However, when asked what state it is for, you will select  foreign.  When you select foreign, you will be given a list of countries to choose from.  Select Japan on this address screen.

To get to this location click the following:

• Federal
• Income
• Scroll down click show more next to Retirement Plans and Social Security
• Start next to IRA, 401k, Pension Plan Withdrawals (1099-R)
• Continue through until you are asked to Enter your 1099-s providers info

We were not asked to enter 1099-s provider information. There’s no place to enter country, etc that you mention. 

You can enter the Japanese pension under Miscellaneous income:

1. Open or continue your return
2. Click on Show more next to Less Common Income under Income & Expenses section
3. Click Start/Revisit next to Miscellaneous Income, 1099-A, 1099-C
4. Click on Start/Revisit next to Other reportable income
5. On the next screen that says Any Other Taxable Income?, select Yes and Continue
6. On the next screen, enter "Japanese Pension" as the Description and enter the amount   
7. Continue and Done.

But before you do, read the treaty between Japan and U.S. first.