Seoyeon and Youngho met a year ago and became lovers, and Sanga and Jaehoon became lovers on the same day. Youngho and Jaehoon are brothers who have been living together for a long time. Seo-yeon, Yeong-ho’s lover, recently moved into the brother’s house and lives with them. Living together, Jae-hoon and Seo-yeon fight over trivial matters almost every day. We fight too often, and sometimes Yeong-ho gets angry, but he lives happily ever after. Jae-hoon also has no complaints about his life with Seo-yeon, but he is tired of Yeong-ho’s and Seo-yeon’s intense relationship. In fact, whenever I see Sang-a, Jae-hoon’s girlfriend, Sang-a, who is having a hard time seeing her as she is a doctoral student, I envy the Young-ho couple. Meanwhile, Jae-hoon has a strange dream of having a relationship with Seo-yeon… Can these two couples be able to maintain their relationship?