The story is set in the period from the end of the Later Han Dynasty to the Three Kingdoms Period in China. In 184 AD, a brave general of the Nanukoku Kingdom, who contributed to Himiko's unification of Japan, decides to take over the "hegemony" of the Later Han Dynasty. He travels alone to Yushu in the Later Han Dynasty, where he meets the three brothers Liu Bei, Guan Yu and Zhang Fei. He works with these three brothers, but soon learns that Liu Bei is an evil person. One day, Liu Bei tries to kill a criminal to test his new sword, but Pei Yu stops him and even cuts off Liu Bei's head. Guan Yu and Zhang Fei are outraged, but Pei Yu sees and points out that the two were not following Liu Bei out of pure heart. Afterwards, Guan Yu and Zhang Fei witnessed Puo Yu's actions and thoughts and decided to make Puo Yu the new Liu Bei, and the three of them took a new oath of brotherhood in Taoyuan.

Note: The story is loosely based on the Three Kingdoms period, using both real and original characters and events from the historical period in Chinese history and folklore of the Romance of the Three Kingdoms.