Ye Fan (Yang Haoming) successfully confessed his love to Tao Tao (Guan Xin) before graduating from college, but Tao Tao died in a car accident that day, and Ye Fan lost his love. Then, Ye Fan accidentally got Tao Tao's old mobile phone and accidentally got through to Tao Tao, who was in her senior year of high school four years ago in 2018. This phone call accidentally changed the fate of the two people, and also started a fantasy love journey of mutual redemption and sacrifice through the magical old mobile phone.