Dr. Haneda was creating advanced giant robot warriors to combat the allies during World War II, but Allied bombs destroyed the facility and killed him before his creations could see action. A decade later criminals found two of the remaining prototypes in the show, # 26 and 27, and used the remote-controlled robots to commit many crimes. Young Shotaro Haneda, Dr. Haneda's twelve-year-old son, did some investigating, and found that the mob was searching for the twenty-eighth robot in the show, rumored to be the most powerful of them all.Racing the villains, Shotaro first finds the robot, along with his father's colleague Dr.
Shikashima, who was also thought to have been destroyed by the Allied bombing. Together, the two keep Tetusjin-28 (the official name of the robot) from falling into the hands of the bad guys, and agree to dedicate him to peace rather than war.For a long time, Shotaro fought crime, with the help of Dr. Shikashima, who would repair Tetsujin-28 when he was injured, and Otsuka, the police officer. Shotaro also fought the alien Magmans, planet Magma invaders who came to Earth late in his career, bearing with them their own giant robots, Magma X and Gold Wolf.