Hi My Sweetheart

Da Lang and Bao Chu has been a couple for three years, and it's coming close to graduation. Bao Chu's mother wants her to marry a wealthy man (they do not know Da Lang actually is wealthy), so she wants her to break up with Da Lang and go and have an arranged marriage. When Da Lang learns about this, he decides to meet up with her on her birthday and reveal his real identity to her, and marry her. And she wants to tell him that she wants to run away with him. But, Bao Chu gets into a car accident and never shows up. Bao Chu's mother lies to Da Lang and says that Bao Chu is going to Europe to marry. Three years later, Bao Chu is a DJ at a radio-station, and is searching for Da Lang, who she hasn't met after the accident. Da Lang/Xue Hai thinks she abandoned him, has given up all hope for love and has transformed himself to handsome player.

Xue Hai recognizes Bao Chu's voice over the radio and decides to buy the radio-station she works at, in order to take revenge on her for leaving him.

Xue Hai continues to persue Bao Chu, truly angering her.

After having insulted Da Lang in a fight with Bao Chu, Xue Hai is punched by her, and threatens to fire her and she threatens to quit. The High School classmate makes them make a deal, that Xue Hai will stop persuing Bao Chu and Bao Chu won't quit. Bao Chu and the High School classmate also officially pronounces themselves a couple because of the Xue Hai incident. The High School classmate and her go on a vacation. Xue Hai follows them, with intention to ruin it.

During his attempt to ruin the vacation, Xue Hai gets all of them drunk. While they are drunk, Bao Chu recognizes Xue Hai as Da Lang and Xue Hai forgets his plan and admits he is Da Lang. They have a reconsiliation, just to forget about it in the morning...

Xue Hai follows Bao Chu again, and she tells him that she wants to meet Da Lang again. Xue Hai grants her wish and appears to her as Da Lang, only to run away in dispair when he don't know if she is innocent or guilty for leaving him. The High School classmate has a meeting with Xue Hai's Da Jie who tells him that Xue Hai has been to school in Hangzhou and that he was hurt by a girl there. He starts to suspect that Da Lang and Xue Hai are the same person.

Bao Chu goes to Xue Hai's home to thank him for contacting Da Lang, and wants him to do it again. During this encounter he learns that she was innocent the whole time, and there is nothing left for him to do but to try to win her back by being himself, and make her forget Da Lang. To accomplish this, he tells her that Da Lang is married. To truly let go, she goes back to Hangzhou to burry the memories she has with Da Lang. When she returns, the High School classmate has figured out that Xue Hai and Da Lang are the same person. Mo Lee from Hangzhou tells Bao Chu the same information.

Extremely mad at Xue Hai, Bao Chu just want to forget about him and Da Lang altogether, and move to another country with the High School classmate. However, during a fire at the radio-station, Xue Hai sacrifices himself for Bao Chu. In that moment, Bao Chu realises that he truly loves her. Xue Hai is brought to the hospital for treatment, but disappears...

Bao Chu searches for Xue Hai, and finally founds him several months later, working at a toy shop. He has lost all his memory and has returned to his old appearence and alias Lin Da Lang. Bao Chu tries to revive his memory, to win him back, but he has already fallen for the daughter of the owner of the toy store. Suddenly, he is kidnapped by a man who is out after the family's money. Bao Chu tries to rescue him, but gets taken hostage too. In the escape, Xue Hai is hit in the head, and regains his memory. However, he lies to Bao Chu and says he doesn't remember her, when seeing her with the High School classmate at the hospital. The family is celebrating his return, he gets drunk and sends a birthday greeting to Bao Chu, blowing his cover.

Waking up and realising he has blown his cover, Xue Hai hurries and breaks into Bao Chu's house and deletes the message. Bao Chu has however already seen it and tricks Xue Hai that she is going abroad with the High School classmate, She tells him to set up a romantic evening for her and the classmate, on which she tells Xue Hai that she knows everything and then proposes to him. Xue Hai says yes and they kiss.