Two families and two sisters who were close friends had a dispute and misunderstanding over a trivial matter, which led to a rift between them. From then on, they became enemies and stopped communicating with each other. Many years later, when the children of the two families grew up, they happily announced the good news of their upcoming marriages. Only then did the parents of both sides realize that the so-called in-laws were "enemies". Suddenly, all the old hatreds and new grudges in the past came to the fore. It seemed that a "family revolution" was quietly unfolding in the two families. Can these two families change from "enemies" to "in-laws", and can the lovers pursue their own happiness?