After being killed by a gang of bandits who desecrate a Buddha statue, a young boy named Ah Kuo is revived by Ultramen and becomes a new Ultraman. Together, the Ultramen battle an army of monsters who are awakened by a failed rocket test.

Through an experiment by Dr. Stewart with animal cells, a monster is created that is given the name Frankenstein. He is a gentle giant, but he escapes his guards and was supposedly killed on a mountain. After several years, a ship off the coast is attacked by a green monster, where the people think of Frankenstein. The green monster attacks the fortified country, in which the army is then called in for help. When a brown monster suddenly appears, Dr. Stewart understands that his Frankenstein was not killed, but has reproduced.