As previously noted, Japanese language education means teaching Japanese to people whose first languages aren't Japanese. The number of all learners in Japan is 191, 753 and they are taught by 36, 168 teachers at 2,012 institutions. The largest learners of 65,130 are from China, followed by 34,919 from Vietnam and 11,432 from Nepal (Agency for Cultural Affairs 2015).
From the view of institutions, 37.1% of all learners learn at Japanese language schools and 27.9% learn at universities and so on. From the view of attributes, 63.4% of all learners are international students and 5.2% are businesspeople and their families. From the view of periods, 31.4% of all learners stay in Japan for less than 1 year and 22.5% stay there for from 1 year to 3 years(Agency for Cultural Affairs 2015).
By my calculation, the number of students per teacher in Japan is 5.3 and it is much fewer than that in overseas, 57.0. It means that much more teachers per student are in Japan compared with that in overseas. It can be said that Japan is much more favored for learners learning Japanese language than overseas.
The Japan Foundation 2016, The flash report of the results of survey about overseas institution of Japanese-language education, viewed 13 December 2016, <http://www.jpf.go.jp/j/about/press/2016/dl/2016-057-1.pdf >