Hajin was just an ordinary girl who was excited about starting her college life. But her dream is shattered when she gets into a car accident. The next thing she knew, she was Matilda Howard living in a fantasy world! Not only that, but she also realizes she has a secret ability; she can turn people's memories into a book! Although she never intended to reveal her ability to anyone, she decides to help beloved King Daden, who suffers from insomnia. That is when Hajin finds out about the dark past Daden has been hiding from everyone

College student Jaeyeon gets hit by a delivery bike. She dies and reincarnates with her memories from past life. As a nanny of a little princess, she somewhat gets used to her new life Except that she suspects the five-year-old daughter of the tyrant emperor is also a reincarnated soul from modern time-just like her! A complete mismatch, the princess and the nanny must collaborate in order to survive in the new world under the tyrant's rule.