Family by choice

A family of three moves into the Oryun Mansion Complex, and Ju Won meets San Ha, the brother she always wanted, for the first time. Despite Joo Won's eager wish to get to know him, San Ha has trouble accepting her due to his family's situation. Meanwhile, San Ha's father meets Kang Seo Hyun, a single mother with a son named Hae Joon.

After growing up together as a family, Joo Won, San Ha, and Hae Joon go to high school together. San Ha and Hae Joon are hot with the girls, causing Joo Won to deal with the onslaught of requests from the girls to deliver their love message to them. Hae Joon catches a suspicious man taking photos of him.

A man visits Hae Jun at school and reveals he is Hae Jun's birth father. Although Hae Jun is initially speechless, he feels relieved to learn that his father has not abandoned him. To find out more about his father, he and San Ha talk with Aunt Yi Hyun to gain insight into his father's character before meeting him in person and uncovering the reasons for his sudden return after all these years.

Ju Won feels exhilarated about going on a date with a boy who is good-looking and smart, but she soon gets disappointed by what he says to her. San Ha and his father are upset by an unwelcome visitor who reminds San Ha of memories he doesn’t want to recall

With Hae Jun’s birthday around the corner, San Ha and Hae Jun get into a big fight. To help them reconcile, Ju Won plans to take them to a rail bike. However, many misunderstandings develop as Ju Won collapses from a cold, and rumors between Dal and Hae Jun spread at the school. Meanwhile, everyone gets ready as Yi Hyun plans to join the birthday party

Hae Jun’s mother, Seo Hyun, unexpectedly visits Yoon’s Kalguksu to repay her debt, leaving Jung Jae puzzled as to what to do with it. Meanwhile, So Hee goes missing after leaving home to meet San Ha. Her disappearance reignites the unresolved conflict between Moo Sung and Jung Hee, and San Ha decides to distance himself from the family as a result.

Hae Jun's mom visited but left without seeing him. After exams, misunderstandings grow between the four friends. Hae Jun's biological father watches his basketball game and suggests he study abroad.

San Han stays in Seoul to look after his step-sister while his mother recovers from surgery. Ju Won goes to Seoul alone to surprise him without telling the rest of the family Meanwhile back at home, Jung Jae collapses from overworking, scaring everyone, especially Hae Jun, who makes up his mind about going to the US.

Ju Won is devastated when San Ha and Hae Jun decide to leave for Seoul and the US. The family feels incomplete. Ten years later, the boys return as adults.

San Ha and Hae Joon return after a decade on Joo Won's birthday. Contrary to her expectations, Joo Won feels indifferent. During the celebration, a shocking revelation about Hae Joon shakes the family.

San Ha's unexpected confession leaves Ju Won stunned. While she denies romantic feelings and insists on a sibling relationship, she's conflicted. Hae Jun's playful marriage proposal upsets San Ha. Meanwhile, Seo Hyun's surprise visit shocks Jung Jae, and an unexpected twist occurs.

San Ha and Joo Won finally confess their love for each other. They worry about breaking the news to their loved ones. Meanwhile, Hae Joon attempts to repay Jung Jae's kindness, but misunderstandings arise when the source of Hae Joon's money is revealed.

Hae Joon discovers San Ha's insomnia and medication use. So Jung visits San Ha secretly, asking him to stay with her and Jung Hee. Dal continues to conceal her feelings for Hae Joon. A major secret between Joo Won and San Ha is on the brink of exposure, thanks to Hae Joon.

Hae Jun feels betrayed by San Ha and Ju Won's closeness. He fears abandonment, a recurring theme in his life. Despite knowing his mother's whereabouts, Hae Jun maintains distance, his resentment growing with each sight of her.

San Ha & Joo Won's relationship is celebrated, except for one. San Ha's injury leads to an emergency room visit, with Jung Jae & Dae Wook rushing to his side. Hae Joon returns to basketball, leaving Dal heartbroken. Meanwhile, an unwelcome visitor arrives at Joo Won's bakery.

San Ha seeks Jung Jae's blessing for his love with Joo Won. Joo Won & Hae Joon play matchmaker for Jung Jae & Seo Hyun, while Dal goes on a blind date. Hae Joon interferes with the match, and Jung Hee plans a move to the UK with So Hee.