Mt. Fuji Vulcanospeological Society  
   Formed in 1970. Involved in karst and lava tree-mold conservation, research work and publication of bulletins. Includes photos and contact information.
   http://www2.wbs.ne.jp/~fujicave/newpage9.htm

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

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

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

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