Three unrelated men and women, Kang Hae-joon (played by Hwang In-yeop), Yoon Joo-won (played by Bae Hyun-sung) and Kim Sun-ha (played by Jung Chae-yeon), each carrying the hurt they received from their parents, relied on each other and spent more than 10 years like a family.Youth time.Ten years later, they met again, facing the entanglement and choice between family, friendship and love.

A family moved in above Zhuyuan's house. It happened that this family had an elder brother that Zhuyuan wanted very much. Later Zhuyuan found out that this family had lost a child. Looking at Shanhe who could not be happy, ZhuyuanDecided to take good care of this brother.By chance, the child Haejun also came to live in Zhuyuan's house due to family changes. In this way, the three children grew up together, took care of each other, were happy together, and became a family.

Zhuyuan has been helping Shanhe and Haejun convey the love of other female classmates since she was a child, even until high school. This really bothers Zhuyuan, and because of this, she is often bullied in school because she only loves people who claim to be her sisters.As for Shanhe's mother, she already had a new family, but Shanhe didn't want to know. In school, Haijun discovered that a stranger had been paying attention to him. Suddenly one day, a man appeared out of nowhere and claimed that he would become a family member with him.!