In many cases, a prospective student first enrolls in a Japanese language institution for 1-2 years, and then takes the university’s entrance exam. Therefore, the choice of the Japanese language institution is very important.
There are two types of Japanese language institutions for oversea students wish to go on to a Japanese university; 1) The preparatory Japanese language courses offered by private universities; 2) Japanese language institution providing Japanese language courses.
For further details, please see the Ministry of Foreign Affairs website “Study in Japan“. The Ministry of Education, Culture, Sports, Science and Technology’s information about “Japanese language institutes” is also useful.