After her parents divorced, Lu Yang moved into her mother's good friend's house and began living with the friend's daughter, Su Gui. Su Gui is smart and gentle, like the warm sun in winter, kind yet unobtrusive. She illuminates Lu Yang's life and shines into Lu Yang's heart. Lu Yang saw her as a sister, a friend, and a mother figure... Later on, Lu Yang didn't want to be her little sister anymore, she wanted to date her. However, after realizing that her feelings for Su Gui had changed, Lu Yang did not want to ruin their current relationship. She was afraid to lose her identity as "little sister". She had to change her dependence on Su Gui and distance herself. But after reuniting with Su Gui at work, the suppressed feelings bloomed like a rose, tightly binding Lu Yang and Su Gui together. Was it a long-term scheme or destiny?...