Transfer student Shen Zhao is forced to become the deskmate of Xie Lin, a genius in science, and accidentally discovers that locked in an iron box he keeps is the blood-stained school badge of Jiang Yu, a young genius who died three years ago. When Xie Lin made a bet to "tell the secret after drawing a hundred sketches", Shen Zhao stole the iron box on a rainy night and revealed an even more shocking truth - the yellowed candy paper in the box actually printed the self-help motto "Shen Zhao, move forward" written by her when she was suffering from depression in her childhood.
The two redeemed each other amidst the trauma of their original family and the whirlpool of public opinion: Shen Zhao tore up the admission letter to Central America to resist his mother, and Xie Lin was disqualified from being admitted due to the truth about Jiang Yu's death. In the end, the comic strip "The Seventh Year of Rust" she created with a paintbrush exploded on the Internet, forcing Jiang Yu's suicide note to be exposed. It was Jiang Yu who was jealous of Xie Lin's talent and tampered with the competition questions, causing the explosion. Xie Lin was seriously injured in saving people but felt guilty for the rest of his life.
Seven years later, the new silver iron box in the space cafe was slowly opened, and the satellite orbit notch overlapped with hundreds of yellowed sketches to form the ∞ symbol. "I dare to kiss you now," Xie Lin's kiss fell on the orbit of the satellite drawn by the milk foam, "because we have finally calibrated the rusty time."
