renew a working visa in japan!!

Does anyone knows how to renew a working visa in japan and what arethe requirements?

Noone can give you precise answer without knowing the TYPE of working visa you have. And there should be plenty of information available on the web, from Immigration Office, Ministry of Justice or Ministry of Foreign Affairs website.

Normally the required documents INCLUDE:
- The application (for extension) form available at the Immigration Office
- Your passport and Alien Registration card,
- Some document that show specific activities you do, the time period, etc., such as employment contract
- Certificate saying that you've paid the resident tax showing the total taxable income (available from the city hall where you live)

http://www.japan-guide.com/forum/quereadisplay.html?0+5...
Someone else has given you the most concise answer to your question here, right at the end :)

Guest,

Again, it probably depends a lot on the exact category of working visa, but isn't it normally the sponsoring company that does all the paperwork? I would talk to your employer first.