Su Jin and An Zihao have been close friends from elementary school to university. They promised to be friends forever. They can't deny the weight in each other's hearts, but they haven't yet fallen in love.
During a fire, he took care of his burned mother in France. She said she would wait for him to come back in China, but when he came back, he had his considerate girlfriend Lin Jing by his side. She repeatedly rejected the affection of Xu Zhengbo, the man who was kind to her, but only for his uncertain love.
He has a girlfriend, but all he can think about is Su Jin. As time went by, Su Jin once thought that she would not love him, but the friendship in the past began to change. During those times with him, he played the role of "Mr. Nice". She could not forget those past, love came quietly, but she did not know it...