The movie is essentially about a love triangle involving two guys and a girl. It is kind of cute and hilariously stupid at the same time, and sort of messed up (in a funny way) in terms of how the relationships unravel and the people act.

So there is Zhang Shenran who is this guy who is completely in love with Cheng Zixin, and has been for years. He only waited so long because she was with someone at the time, but now that she is single again he finally approaches her. They happen to work in buildings that are facing opposite of each other and communicate through sticky notes and hand signals behind their office windows. However, Shenran has a bad tendency to be distracted/lured by other women despite how much he likes Zixin. He claims it is due to his "high testosterone level", which ultimately is what causes problems in the development of their relationship. Then there is Fang Qihong, the "Martian." He is morally speaking the popular choice because of the whole concept: 9 out of 10 men cheat, the last one is thinking about it and the 11th one is neither (Martian), which would be this guy. He is first introduced to the story when he saves Zixin from a car accident. At the time he dressed and acted like a homeless person, but was actually an architect who lost all inspiration and started drinking. However he becomes the one who cheers Zixin up from her last relationship, and she also inspires him to work again.

There ends up being so much bouncing back and forth (done in an annoying but comedic way where I ended up not minding it at all) and it actually leaves the viewers trying to guess who the female protagonist will end up with.