If you want to study in Japan be prepared to spend a lot of money if you don't have scholarship. If you want scholarship you can try the Monbugakusho Scholarship given by the government of Japan every year (check Japan Embassy for details). If not, there are local Japanese prep colleges here that prepare you for your university studies in Japan. I remember in the past there were Study-in-Japan fairs as well which you can definitely check out. Go Google search them. =)

Japan is famous for mainly engineering since it's a technology advanced country. Yes, you need to at least pass JLPT Level 1 (native-level) exam because their medium of instruction is in Japanese. However, in certain unis their Master programmes are conducted in English.