The story is based on the death of Ye Xiaoxiao. In order to find out the cause of her death, her boyfriend Chu Yi looked through Xiaoxiao's diary and found a girl named Shen Lin in it. He also described that in one semester, Shen Lin transferred to another school and got acquainted with Xiaoxiao.
Later, as if his soul traveled through time, he returned to a year ago from the perspective of a bystander. No one could see him, as if he didn't exist. He saw Su Chenlin's arrival a year ago again in this state.
Su Chenlin is a very cold girl. Xiaoxiao tried to be friends with her, but was rejected. No one seems to have noticed Su Chenlin, no one except Xiaoxiao pays attention to Su Chenlin, and now, Xiaoxiao is also isolated by everyone.
Finally, a year later, Xiaoxiao committed suicide, and Shen Lin also miraculously disappeared.
Chu Yi could not accept the fact that Xiaoxiao committed suicide. After several investigations, he found a radio host, Leng Xiatian, and learned that Xiaoxiao suffered from a serious mental illness. Shen Lin was just a fantasy. Her hope that she could have a true friend was a very serious delusion, and the diary was also made up.
Later, Chu Yi met Leng Xia Tian. She looked exactly like Su Chenlin...