An inventor and his family try to raise funds to feed a giant monster named Daigoro so that he doesn't shrink. Meanwhile, a meteor lands into the sea bringing with it another giant monster named Goliath. Will Daigoro be able to stop Goliath?

Ichiro Miki is a child living in the industrial district of Kawasaki, where his parents' constant struggle to make ends meet often leaves the schoolboy alone. Constantly teased by a bully nicknamed Gabara, his only friends are toy consultant Shinpei and fellow classmate Sachiko. Ichiro turns to escapist dreams of Monster Island where he befriends the equally bullied Minilla.