Although they are not biologically related, Kim San Ha (Hwang In Youp), Yoon Ju Won (Jung Chae Yeon), and Kang Hae Jun (Bae Hyeon Seong) are very close. The three spent their teenage years growing up with Ju Won’s father, Jeong Jae (Choi Won Young), and San Ha’s father, Dae Uk (Choi Moo Sung), who did their best to give the children—who were overcoming the traumas of their past—a happy childhood. Once they reached adulthood, however, San Ha and Hae Jun set out to find their biological families, drifting apart from Ju Won. Ten years later, the five members of what was once a de facto family reunite, but things are no longer as they once were: Ju Won harbors resentment after feeling abandoned by San Ha and Hae Jun, while the two young men must come to terms with their newfound feelings of love for Ju Won and their own family issues. Will these siblings by choice be able to face the feelings they have for one another, and will a romance blossom between them?