Statement of earnings
When filing a tax return in your home country you may be asked to include a statement of your annual income from your contracting organization. This statement is known as a gensen-choshu-hyo 源泉徴収票 , and is issued to you around the end of January.
It indicates the salary received, and tax paid in Japan from January 1 – December 31 of the previous year.
Please keep in mind that while those on the same contract year under the JET/ Sendai Hello World Programme will be earning the same amount, the figures on your statement with vary according to your nationality (differing tax liabilities); length of time on JET (first years and leavers will only do a partial year, plus 3rd years may be different to 1st/2nd); where you live in Japan (prefectural and municipal tax liabilities); and whether you have dependents.
The JET Programme General Information Handbook has further information on the taxes that are paid during your time in Japan. For current and accurate information on filing procedures for home country taxes, it is advised that you contact the tax authority in your home country.
The Kumamoto JET website has comprehensive guides for US JETs needing to file tax returns here: http://kumamotojet.com/U-S--Taxes.php