Bi Sheng and Bi Qi are street brothels, and they are very close, and are known as the two Bigs of Street. Because Sheng owes gambling debts, Qi asks her boyfriend Long to help her out, and she has a feud with Xiyangzai. Later, Qi is kidnapped by Xiyangzai. Sheng and Long go through life and death to find Qi, and gradually fall in love. After Qi is rescued, she finds out about Sheng and Long's relationship, and gradually becomes estranged from Sheng. On the other hand, Sheng meets the old policeman Mai Sir and becomes his friend. Mai Sir has a father-daughter relationship with Sheng. Mai Sir chases Long several times, but is stopped by his boss Liang Sir. It turns out that Long is an undercover agent, directly under Liang Sir. Later, Liang Sir is killed by Xiyangzai. Long is pursued by Mai Sir, and has no way to prove his identity. Xiyangzai's private business is busted, and he kidnaps Mai Sir's son Xiaojie, forcing Mai Sir to kill Long for him. In the crisis, Sheng, who is trapped in a sack, breaks free and rushes out, and a bloody man rushes towards Xiyangzai...