Xiao You returns from Canada to see Xi Men. He later tells her the story about his first love, Xiao Geng. After hearing the story, Xiao You searches for the thing Xiao Geng wished to show Xi Men.
Xiao You returns to Taiwan to see Xi Men. He is shocked at first, but pleased and agrees to meet her later. Mei Zuo arranges for Xiao You to meet them at the club that night. Xi Men tries to hide his feelings by flirting with other girls. A guy approaches Xiao You when she arrives, but she turns him down. Xi Men offends Xiao You by telling her she can be more like him. After he tells her that they are too different, Xiao You walks up to the stranger and flirts with him. Xi Men then drags her away. Pestered by Xiao You, Xi Men decides to tell her about his first love.
In a flashback, Xiao Geng, Xi Men's childhood friend, interrupts him while he is with another girl. He receives a call from yet another girl, Julia, and leaves to go see her. In the morning, Xi Men's mother asks him to stand in at a party for his father, who is in Hong Kong with his mistress. Xi Men is saddened by his family situation, which has "long been shattered." Xiao Geng arrives and cheers him up with snacks. When he protects her from hitting her head, their faces come close together. She closes her eyes, but he quickly gets up.
Later, Xi Men and Mei Zuo are at a club flirting with girls. At the same time, Xiao Geng is leaving karaoke with her friends. They go to see a swimming pool on top of a skyscraper. As the sun rises, Xiao Geng sees something in the distance. She leaves a voicemail, telling Xi Men to meet her at the building at 5 AM. Xi Men immediately decides against going and spends the night in the arms of another woman. The next morning, Xiao Geng is waiting for Xi Men at his home. She begins to cry and tells him simply "goodbye". Xiao Geng never comes back, but sends him a note explaining her feelings.
Xi Men finishes his story and expresses his regret about not knowing what Xiao Geng wanted him to see. Sometime later, Xiao You investigates a building. After a fruitless night, she returns home to a concerned aunt. Xiao You pleads with her to not interfere in the "most important time of my life." The next night, Xiao You inspects another building. Before she turns to leave, she discovers the thing that Xiao Geng meant for Xi Men to see. Xiao You calls Chen Qing He, attempting to locate Xi Men. Mei Zuo and Dao Ming Si happen to pass by. They have not seen him either, but offer their assistance.
Meanwhile, Hua Ze Lei attempts to get Xi Men to admit he has feelings for Xiao You. Xi Men, however, refuses to disclose anything, instead saying that he already has plans to avoid her. By 4:30 AM, Mei Zuo and Si are ready to give up searching, but Xiao You wants to continue. They bring her to one last bar, where they finally find Xi Men. Xiao You grabs him and rushes to the building. They arrive just before the sun rises. In the distance, the sun's glare allows a sign to be read as "Xi Men, my love". Xi Men starts to cry as he comprehends the words.