February and March in Japan is tax season. Filing a tax return isn’t easy at the best of times, but doing it in another country can be particularly challenging.
Fortunately, if you work for a company and that’s your sole source of income in Japan, they will take care of everything for you. However, those who are self-employed or have multiple sources of income will have to file a Tax Return "Kakutei Shinkoku - 確定申告".
The two main forms of tax are Income Tax "Shotokuzei - 所得税", and residence Tax "Juminzei - 住民税". The rates you pay for both kinds of tax are calculated according to your earnings.