in august 1984, riki choshu had formed ishin gundan with animal hamaguchi, isamu teranishi, yoshiaki yatsu, masa saito and kuniaki kobayashi to feud with antonio inoki and new japan pro-wrestling. however, just as the feud was heating up, tensions both in and out of the ring forced ishingun and a few others to leave njpw that september. the next month, they formed japan pro-wrestling and also announced a co-promotion with all japan pro wrestling. masa saito briefly went back to north america but returned to japan in 1985 and joined in the new promotion.