Here is a list of academic conference organizers in Japan. When you click on the link you can see the translated version of the posts on the website of each academic association. Please kindly note that the majority of Japanese academic associations hold their conferences in Japanese and scholars who are not members usually are not allowed to present (regardless of the quality of research) at the conference. In order to be a member, the applicant must be referred by a current member of the society. Some Japanese academic societies are more flexible and do not require a membership to present at a conference.