If you are planning to study in Japan, you really need to check out following sites:
JASSO is the place to start if you want to study in Japan.
This site is also from JASSO and has more or less the same information as on their main website.
This is a comprehensive guide from the Ministry of Foreign Affairs in Japan.
If you are planning to learn Japanese in a language school in Japan, following links might help you:
Japanese Language Schools in Japan
Organizations as bridge to language schools in Japan
Scholarships to study in Japan
Learning Japanese by working in Japan: Japanese Exchange and Teaching (JET) Programme
Aiming primarily to promote grass-roots internationalisation at the local level, the JET Programme invites young college graduates from around the world to participate in internationalisation initiatives and be involved in foreign language education at Japan’s local government offices, Boards of Education, elementary schools, junior high schools, and senior high schools.
See also ’25 reasons to join the JET programme (and 8 reasons not to)’ on the website of Tofugu.