Xiaogang (Sakurai Sakurai), the only son of the Takata toy store owner, inherited the genes of his parents and invented the giant robot dog that can be used to fight. He and his girlfriend Xiao Ai (Shagi Fukuda) form the righteous "Xiao Shuangxia" and make continuous efforts to protect world peace. Their main opponent is the Durham Thief Party, which is composed of the female thief head Durochi (Kyoko Fujita) and his one fat and one thin entourage, Tong Zira (Kobayashi Kendo) and Boyagi (Katsuhisa Shinase). Duolongzhi works for the skeleton shellfish, the god of thieves, and they are ordered to look around for fragments of skeletal stones that can achieve any wish. The father of the young girl Xiangzi (Akira Okada), Dr. Hai Jiangtian (Abe Takashi), is an archaeologist who suddenly disappeared in the process of searching for the skeleton stone. In order to stop Skeleton's plot to perish the world, Xiao Shuangxia, who learned the details from Xiangzi, launched a series of wonderful and fierce battles with Duolongzhi.