The Society for the Promotion of the Open University of Japan is the publisher in Japan founded in 1984.
According to PR-model, ua-book.or.jp is ranked 1,999,751st in multilingual Wikipedia, in particular this website is ranked 174,904th in Japanese Wikipedia.
The website is placed before mytwelve.co.kr and after ryumatsuyama.com in the BestRef global ranking of the most important sources of Wikipedia.