The odd world in this shooter made for quite the conversation piece in its day. Players control either Idaten or Benten, celestial warriors out to bring an end to the tyrannical rule of the emperor of Planet Builder, who holds muscular prowess to be the supreme virtue of the universe.

Botei, the unbeatable champion of the Intergalactic Bodybuilding Contest, have run dry on his protein supplies, so he decides to enslave various planets to set up factories of protein for his own use. In order to stop him, the Heavens send out his two champions, Idaten and Benten, who now must face Botei's Builder Army.