Students across the world who have been unable to enter Japan for study due to the current COVID-19 entry ban mostly feel that their mental health has deteriorated, a private survey showed Thursday.

Davide Rossi, who runs a Tokyo-based company helping foreign students study in Japan, said his online survey conducted for 10 days through Sunday found that 58.4% of 3,115 respondents felt their mental health "significantly declined" and 26.2% "slightly declined."

Japan has banned entries by foreigners in principle since Nov. 30 following the global spread of the highly contagious omicron virus variant.