The story begins with Qi Yue planning to confess her liking to the basketball team captain, Yuan Yi. She wrote a love letter and plans to pass it to him. Being as careless as only she can be, she has made her confession to the wrong person, who happened to be the school's devil, Ah Meng! (her junior, a first year student in school). She is so shocked and embarrassed to see Ah Meng's face that she drops her love letter in front of Ah Meng and runs away. Ah Meng picks up the letter.

Ah Meng is amused by the whole thing and decides to have some fun with Qi Yue. He threatens Qi Yue to print a thousand copies of her love letter and let the whole school know of her liking for Yuan Yi. In order to stop Ah Meng, Qi Yue agrees to be his 'runner'.

With Ah Meng's continuous bullying of Qi Yue, she is driven to stop all the nonsense by confessing her liking to Yuan Yi again. In this way, she will not be afraid of Ah Meng's disclosing the love letter anymore. To Qi Yue's surprise, Yuan Yi has a similar liking for her.

While Qi Yue assumes that the whole ordeal with the devil is going to end, she receives another piece of bad news - her mom is going to marry the school's chairman who is also Ah Meng's father! That means Ah Meng is going to be her stepbrother.

Qi Yue's love letter is being put up on the school notice board and she misunderstands that it is Ah Meng who did it. She confronts him and storms off. After realizing that she has misunderstood Ah Meng, she apologises to Ah Meng and pleads him to hit her so that she feels better. Ah Meng kisses her instead! Yuan Yi happens to see them kissing and confronts their relationship, Ah Meng yells at Yuan Yi, saying that he wants Qi Yue. After Yuan Yi runs away in anger, Qi Yue looks at Ah Meng and begins to sob. After Qi Yue walks away in tears, Ah Meng has a strong feeling of guilt.

Yuan Yi regrets not believing in Qi Yue and returns to her, asking her out on a date. Qi Yue agrees happily. On their first date, they met Ah Meng again. Qi Yue and Ah Meng have some misunderstandings and they went separate ways.

After the date, Qi Yue left for home. After she took her bath, she fainted and was saved by Ah Meng's father. He brings her to his house to take care of her while her mom was away on a trip. Ah Meng and Qi Yue meet again at his house. She knows from Yuan Yi that she has misunderstood Ah Meng again. Seeing Ah Meng has injured his hand, she offers to clean the wounds for him. Sitting on Ah Meng's bed and putting medicine on his hand, she realizes Ah Meng is staring at her intensely and this makes her heart pound. Qi Yue wakes up and finds herself sleeping on Ah Meng's bed. Apparently, both have fallen asleep and Ah Meng's father has carried her to his bed.

Qi Yue finally realizes that the person she likes is Ah Meng. She tells Yuan Yi the truth and walks away. In the evening, she sits alone at the playground, crying softly to herself for hurting Yuan Yi. Ah Meng finds her and comforts her. She takes a ride on Ah Meng's bicycle. They had a minor accident and both fell on the road, unharmed. Qi Yue asks Ah Meng why is it always so dangerous to be with him. Ah Meng replies her that he cannot stop the dangers but he will protect her. Ah Meng kisses Qi Yue passionately on the road!

Due to their relationship as future stepsiblings, they keep their ?lover? relationship in the dark. Except for some close friends of Ah Meng & Qi Yue, nobody knows of their relationship.

Ah Meng's buddy, Yang Ping, who is in love with Li Xiang, is unhappy to see Ah Meng and Qi Yue together. He wants to get rid of Qi Yue so that Ah Meng can be with Li Xiang. At the school's rooftop, he ambushes Qi Yue and wants to kill her. Li Xiang hesitantly tells Ah Meng of Yang Ping's plan and Ah Meng rushes to Qi Yue's rescue. He beats up Yang Ping and brings Qi Yue home. At home, Qi Yue confesses her liking to Ah Meng and he hugs her, saying that he is happy to know that she likes him.

One fine day, there's this cute-looking young guy who comes to Qi Yue and confesses his liking for her. This shocks Qi Yue and her whole class as he storms into her class and tells her that he likes her and wants her to convey a message to her boyfriend that he wants Qi Yue! His name is Ah Rang.

Yuan Yi casually mentions this to Ah Meng and he storms away in anger. In the evening, he tells Qi Yue that nobody is more confident than him in liking her and she belongs to him only. Qi Yue smiles at his possessiveness.

Qi Yue goes to Da Zhi High School to look for Ah Rang and realizes that he is Ah Meng's younger brother. Yuan Yi tells Ah Meng about this and Ah Meng storms off to look for Qi Yue. At seeing Ah Rang and Qi Yue, he trips Ah Rang and makes him fall to the ground. Ah Meng grabs Qi Yue's arm and walks away. He does not want to talk about his brother at all. Ah Rang is actually harmless, his intention is to attract Ah Meng's attention. He longs for his brother's affection. While arguing with Ah Meng, Ah Rang suffers an asthma attack and Ah Meng rushes him to the hospital. Both brothers patch up. Ah Meng was told that Qi Yue fainted in the hospital. Ah Meng runs towards her. At her home, Ah Meng reprimands Qi Yue for being a busybody and tiring herself out, which is the cause of her fatigue. He is concerned about her and Qi Yue is happy.

Ah Meng's grandma suspects that Ah Meng and Qi Yue are seeing each other. She plans to matchmake Ah Meng with a rich girl, Mei Di. Qi Yue feels sad. At the same time, Qi Yue's first love reappears as her school lecturer (Ah Sheng)! This causes Ah Meng to be jealous and he feels insecure. Ah Meng rejects Mei Di and she left wishing Qi Yue and him happiness. Similarly, Qi Yue tells Ah Sheng that she likes Ah Meng and he goes back to his girlfriend.

While things seem to be going fine again, Ah Meng's mom comes back and wants Ah Meng to go to France with her to pursue his studies. When Ah Meng finally agrees to go with her, Qi Yue is heartbroken. At the playground, Ah Meng tells Qi Yue that she can continue to date other people while he is away but he will always like her only. They hug at the playground.

A year later, Ah Meng returns for Christmas and they meet at the place where Ah Meng first gave her a handmade Christmas tree. He tells Qi Yue that he's back and they kiss.