In a previous life, Princess Yuko and her knight Harold loved each other but could not be together because of their social positions, so they promised to reunite after reincarnation. Yuko is reborn first and spends decades searching for him in modern Japan. When she finally finds Harold’s reincarnation, he is still a high school student, turning their old promise into a complicated question about whether a bond from another life can—or should—resume under very different present-day circumstances.