During the Republic of China era, Jingwu School successor Long Wu participated in underground bare-knuckle fights to save his seriously ill younger sister. After defeating a foreign boxing champion with a single punch, he was hunted down by Zhou Batian, forcing the siblings to flee to Shanghai. In the French Concession ring, he crushed Japanese warrior Yamamoto Saburo and saved Wang Zhentian, the master of the Wang Family Martial Arts Gym, being appointed as head instructor. He defeated Yamamoto Taro's provocation ten-to-one, taught Green Gang young master Ye Shuang a lesson at the theater, and single-handedly repelled a hundred-man siege, winning the admiration of gang leader Ye Xiong. At the international martial arts tournament, Yamamoto Taro kidnapped Long Xiaoyue as leverage. The Green Gang righteously helped rescue her, and Long Wu defeated Tushen—who had injected himself with forbidden drugs—shattering the forces of the Japanese Martial Arts Dojo and glorifying Chinese kung fu across the Shanghai Bund.