Twin of Brothers is set in a period of dynastic change in Chinese history. Wacky wannabe swordsmen Chung (Raymond Lam) and Ling (Ron Ng) accidentally acquire the mysterious "Longevity Martial Arts", which is rumored to be the key to a huge treasure. The target of numerous people who covet the treasure, the two friends adventure through China despite the danger. In their journey, Ling meets two girls from two opposing sects (Leila Tong and Nancy Wu), while Chung falls for the sister (Tavia Yeung) of the future emperor of China. With their extraordinary experiences, will the two become heroes amidst the historical turbulence?