Xu Zuo, a tomboy who was known as a "talent" since she was a child, discovered that she had a different sexual orientation from ordinary people when she entered adolescence. From then on, she became gloomy and melancholy, did not communicate with others, and isolated herself in the lonely city of heart, alone under the windy window. At the age of seventeen During her ignorant years, four young and beautiful girls met her, and they performed a series of emotional stories about the joys and sorrows of youth, soothing Xu Zuo's dry heart with pure friendship. Among them was a beautiful woman named Zhou Zifu, who smiled like a flower, was innocent, straightforward and rebellious, because After a small quarrel with her father, she took her twin sister Zhou Zilan and her friend Wang Sisi out of school to work at Xu Zuo's house for "summer vacation". Xu Zuo, who had just begun to fall in love, secretly fell in love with her in his heart. However, at this time, she was already the official girlfriend of her younger brother Xu You. In the complex and tangled emotions of friendship and love Sensually, she chose to bury this secret deep in her heart, and Zhou Zifu, who had a high emotional intelligence, had already seen through her mind. They kept silent to each other and maintained the friendship silently, but they didn't know that unknowingly, their feelings for it had slowly crossed the bottom line of friendship. After experiencing all kinds of joys and sorrows, her love with Xu You did not blossom. After breaking up with him, she chose to return to school and disappeared into Xu Zuo's world. Only one left earring was left for her. It feels shapeless and marked. In order to commemorate the dark and bitter scenery of youth, Xu Zuo chose to integrate this left earring into his own flesh and blood...