This article attempts to explore the commonalities of behaviors among the three evildoers in the Korean old novel and how those features are connected to the subject of this work. They are instrumental in the course of the narrative. In Chapter 2, we examine how the three evildoers are embodied in three parts. The results show that they share three similarities. 1) These three evildoers must serve saviors as one’s master. 2) They are very poor and have nowhere to go. 3) Moreover, two men out of these three evildoers have similarities. For example, Kyo-chaeran and Dong-chung are from the nobleman, and they are smart and act charming. Moreover, Dong-chung and Naeng-jin are talented at gambling, and live a wild life of wandering. In Chapter 3, we examine how the three evildoers’ three similarities appear in their behaviors. First, we consider how they obey “the relationship between the master and the servant.” Unfortunately, they all betray their master. They attempt to harm one’s master, and even intent to kill another. Especially, the evil men have sex with a master’s wife. Second, we discuss how the three evildoers have places to stay, and make an effort toward this purpose. Kyo-chaeran first becomes a Yu-yeonsu’s concubine. However, after having sex with Dong-chung, she eventually becomes his wife. Additionally, Naeng-jin betrays Dong-chung. Consequently, Dong-chung is killed by the emperor. After Dong-chung’s death, Naeng-jin makes a wife of Kyo-chaeran. They all aspire to have a home and a family. However, because of betrayal and promiscuous sex, they are all going to die. Third, we emphasize that the problem of evildoers’ “serving” is closely connected to this work’s theme. This kind of ethic is realized in Yu’s family as well as an extended family. Furthermore, its ethic contributes to maintaining a hierarchical order in the family. The author stresses two things in this work: 1) do your best to serve, 2) if you perform those duties, you will be fully rewarded. Nevertheless, if you fail to fulfil your duties, you will receive a heavy punishment. Thus, the three evildoers come to the end of their lives. The author regards betrayal as evil.