Gong Ma Sung (Choi Jin Hyuk) is a successor to the Sunwoo company. Life seems to be going well until he gets into a car accident while trying to help a woman. Since then, he suffers from memory loss where his memory lasts only a day. Every night before bed, he writes notes about what happened to him that day and the next morning he memorizes everything that happened. Gong Ma Sung then meets Joo Gi-Bbeum (Song Ha Yoon), a formerly well-known actress, and falls in love.