This story is the novel version of Yihuan Comics "The Spirit of the Blue Sea"
They are enemies, destined to fight to the death.
Moreover, there are still grudges from the previous generation.
...
In the late Ming Dynasty, pirates in the South China Sea became increasingly rampant, with Ningjiabao being the most powerful. The imperial court sent troops to encircle and suppress him many times, but all failed.
General Shao Zhixun took the initiative to request an order to go to the South China Sea to suppress bandits in order to protect his younger sister Shao Juanjuan who was about to get married. Ning Haier, the daughter of a pirate, sneaked into the military camp alone and was caught to save her brother Huo Ye who was captured. Businessman Michelle agreed to help Haier escape in order to get back the things she had snatched.
. . . . . .