Hou Deshi (played by Ma Dezhong) was born into a gangster family, but he passed the mediator qualification certificate and became a mediation expert who made a living by his tongue. Lawyer Ouyang Ji (played by Li Sijie) is Hou Deshi's friend and competitor. He is extremely rational and is used to solving all problems with the law. The two often quarrel because of their different beliefs. Ouyang Ji's father Ouyang Bian (played by Huang Guangliang) often favors Hou Deshi in conflicts, which makes Ouyang Ji indignant. Wu Ruiyi (played by Xu Zishan) has been dependent on her autistic sister Wu Ruijia (played by Zhu Qianxue) since childhood. After growing up, she came to Ouyang Ji's law firm to work and make money because of her unsatisfactory career and love. She met lecturer Hou Deshi in the mediation class. Hou Deshi's principles and attitude towards people made Wu Ruiyi admire him very much. As time went by, a sincere relationship developed between the two.