Kansai Independent League
From BR Bullpen
The Kansai Independent League was formed in Japan in 2008, with the first games being played in March 2009.  The four team league is designed to be a farm system for the larger Japanese baseball teams. 
Notable players include Eri Yoshida, the first female pro player in Japan.
also used the Wikipedia article about the league,  as they quote several trusted Japanese newspapers as sources, should be reliable.