The story begins with Qi Yue (Rainie Yang) planning to confess her liking to the basketball team captain, Yuan Yi (Kingone Wang).

Sitting on Ah Mon's bed and putting medicine on his hand, she realizes Ah Mon is staring at her intensely and this makes her heart pound.

Qi Yue wakes up and finds herself sleeping on Ah Mon's bed.

In the evening, he tells Qi Yue that nobody is more confident than he is in liking her and she belongs to him only. Qi Yue goes to Da Zhi High School to look for Ah Rang and realizes that he is Ah Mon's younger brother.

Yuan Yi tells Ah Mon about this and Ah Mon storms off to look for Qi Yue. Ah Rang is actually harmless, and his only intention is to attract Ah Mon's attention. While arguing with Ah Mon, Ah Rang suffers an asthma attack and Ah Mon rushes him to the hospital. Ah Mon was told that Qi Yue fainted in the hospital. At her home, Ah Mon reprimands Qi Yue for being a busybody and tiring herself out, which is the cause of her fatigue.

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 Mon, Qi Yue agrees to be his 'runner'.At seeing Ah Rang and Qi Yue, he trips Ah Rang and makes him fall to the ground. He is concerned about her, which makes Qi Yue happy.Ah Mon's relationship with Ah Rang is better so when Ah Rang gets bullied, Ah Mon comes to his rescue.Ah Mon replies her that he cannot stop the dangers but he will protect her. Due to their relationship as future step siblings, they keep their romantic relationship in the dark.Except for some close friends of Ah Mon & Qi Yue, nobody knows of their relationship.Natalie shares the group photo of Kenneth, Jazz, Stephen and herself online today: "Nothing is more important than my brothers' happiness and I may be becoming part of the brothers' group.