Led by Breaking Boss, the Andro Corps had finally achieved world domination, forcing humans into slave labor in robot factories and other facilities. However, a legend persisted among the people. It spoke of a savior named "Casshan," who took the form of a man and fought against the robots, and who would one day liberate humanity. One day, a girl named Luna Kozuki infiltrated the Andro Corps' largest robot factory and attempted to help the prisoners escape, but she failed. Just as Luna was about to be executed, the legendary savior finally appeared...