First Love Under the Sun tells the story of the heroine Chang Xiaoxiao's student days, work, love and friendships that go up and down over time. Chang Xiaoxiao once said something to Yang Zheyu. In this movie called "First Love". I no longer care whether you loved me or not, I just need to remember that I once loved, believed, persisted, throbbed, sad, and sweetly very simply, and that is enough. Since you are not the end of my happiness, how can I let my heart stay here? I will keep moving forward until I find my happy ending...