Alisa, a librarian at the Royal Library, finds a diary of unknown ownership. The diary, in which letters appear of their own accord, is a "magic diary." One day, while looking at the diary, Alisa is suddenly transported to another place. It is a world 11 years in the past, just like the diary. There, she meets a boy named Louis and they develop a strange friendship. Meanwhile, at a ball to select the queen, which Alisa attends without much thought, the king shows a strong interest in Alisa... What is the secret of the two worlds that the diary connects, and what is the new fate that surrounds her...?