Pei Ran and Luo Qingshan have been together since high school, three years and counting. Luo Qingshan is extroverted and overly affectionate, while Pei Ran is the opposite, more shy and reserved, and has mysophobia, making him averse to most of Luo Qingshan's affections. This often leads to them disagreeing or Luo Qingshan pleading and begging Pei Ran to relent, but they are otherwise comfortable. However, Pei Ran will give in as much as possible when Luo Qingshan's birthday comes around.
As much as he hates it, he goes out to a karaoke place with Luo Qingshan, along with a group of his friends. Everyone is drinking and smoking, two things Pei Ran has trouble being around. Another person who happens to be there is Su Nian, Luo Qingshan's close friend, who is more forward and affectionate with Luo Qingshan than Pei Ran would like. After a lot of drinking, Luo Qingshan heads to the bathroom. After a while, Pei Ran checks on him, only to find him and Su Nian kissing outside the bathroom.
Stunned, Pei Ran isn't sure what to do until Luo Qingshan's roommate Yan Zhun comes by and gets Pei Ran out of there. Comforted by Yan Zhun, Pei Ran spares no time to gather all of Luo Qingshan's things and break up with him the next time they meet. Luo Qingshan isn't ready to give up just yet, going out of his way to get close to Pei Ran and beg for his forgiveness. Pei Ran holds firm, thanks in part to the friendship he's found in Yan Zhun, but it isn't long before Yan Zhun makes it clear: he likes Pei Ran more than a friend.
Fresh out of a painful breakup, with an ex still hot on his heels and a love rival in Su Nian who bad-mouthes him any chance he gets, can Pei Ran find it in himself to fall for someone else? Or has the well of love been poisoned for good?