Humanity faces an assault from demonic entities known as Oni. With no other means of defense available, scientist Dr. Saotome develops a line of giant robots that channel the enigmatic power of Getter Rays, providing the strength required to combat the Oni. The most powerful of these machines is Getter Robo, and Saotome must recruit three distinct individuals to pilot it: martial artist Ryoma Nagare, criminal boss Hayato Jin, and monk Benkei Musashibou. United as the Getter Team, they battle to eradicate the Oni threat once and for all.