Income Tax Guide for Foreigners – National Tax Agency
Please see the below guide for an explanation of matters associated with filing Tax Returns for Foreigners in Japan provided by the National Tax Agency, including:
Withholding Tax System
Deductions from Income
Deductions from Tax
Who must file a tax return
Tax refunds
Calculating your Tax
Special measures provided by international tax treaties
etc.
2012 Tax Returns should be filed from Monday, February 18th, through Friday, March, 2013.
http://www.nta.go.jp/tetsuzuki/shinkoku/shotoku/tebiki2012/pdf/43.pdf