Visa
ビザ
Whether or not you will need a Visa for your visit to Japan depends on several factors;
The 'Ministry of Foreign Affairs of Japan' (MOFA) provide a very useful Guide to Japanese Visas with up to date information and guidance on the application process.
Chinese, Russian and Philippines Nationals will need to visit their local Embassy or Consulate for all visits to Japan, even short stays.
Most European, North American and certain other Oceanic or African countries have Visa exemption arrangements which allow short stays (generally 90 days or less) for tourism and unpaid activities.
If you intend to work or earn money from your activities while in Japan or if you wish to stay for longer than allowed in the exemption for your Nationality you will almost certainly be required to obtain a Visa.