A Tokyo-based university says about 700 of its foreign students quit or became unaccounted for in the current academic year.
The Tokyo University of Social Welfare says the students -- from Vietnam, Nepal and other countries -- have left or lost contact with the school since April last year.
The students belonged to a campus in Tokyo's Kita Ward, one of the university's four in Japan.
Many of the about 5,000 foreign students at the university hold visas allowing them to study in Japan and enroll as research students.
University officials say they regret that some students have quit or gone missing. They say they will step up measures to address the problem.
Japan's education and justice ministries plan to launch an investigation at the university.