Mt. Fuji Vulcanospeological Society - The only organization in Japan focussing on Vulcanospeleology. Contacts, photos and council members list. - http://www2.wbs.ne.jp/~fujicave/nnp2.htm
Edogawa Caving Club - Formed in 1982. Offers SRT training and joint expeditions with other groups. Includes lists of longest and deepest caves and contact information. - http://member.nifty.ne.jp/Edogawa/index-e.html
The Speleological Society of Japan - Formed in 1975 and consists of councils and special committees. Involved with karst conservation, underground safety and research. Includes contacts. [Japanese and English]. - http://www.netlaputa.ne.jp/~ssj/index-e.html
Tokyo Speleo Club - Meets monthly in Shinjuku. Includes membership requirements, meeting schedule, bulletin board, photos and contacts. [Japanese and English]. - http://www.age.jp/~speleo/index-e.html
Speleological Survey Group of Yamaguchi University - Began in 1960 and main explorations have been done in the limestone area of Akiyoshi-dai. Includes photos and contacts. [Japanese and English]. - http://sty.sv.cc.yamaguchi-u.ac.jp/~speleo/caveinde.html