Gong Ma-Sung is a successor to the Sunwoo Company and he is an expert in the field of cranial nerves. One day, while trying to help a woman who he happens to meet, he has a car accident. Gong Ma-Sung suffers from short-term memory loss after the car accident and his memory lasts for only one day. Ever day, he writes down notes about what happened to him that day. The next morning, he memorizes the written notes that he wrote the night before. Gong Ma-Sung then meets Joo Gi-Bbeum. She used to be a popular actress, but she is not anymore. They fall in love with each other.