Song Zhehang is the boyfriend of Li Rui, the legitimate son of a wealthy family, a poor man with nothing but a face;
Li Jinghe, Li Rui's best friend, the second youngest son of the Li family who is the most playful in the circle, and likes gentle and clean boys the most;
People like Song Zhehang were born in the mud and maintained their proper "nature" very well. They would always do anything to get what they wanted.
An occasional act of kindness helped Li Jinghe, who had humiliated him the most, just because he was Li Jingren's younger brother. But it created a fate that was constantly cut and untangled.
But you have to pay back your debts, because you should.
Later
Li Jinghe: "Song Zhehang, let's be together"
Song Zhehang: "It's a collision."
Li Jinghe: "You dislike me"
Song Zhehang: "It's really a collision of numbers."
Purpose: Paying back debts is a matter of course.