Kyouko is a 16-year-old princess from the 30th century, soon to become queen. However, if she ascends the throne, she must leave school, which she is reluctant to do as no one there knows her true identity. To avoid this, she embarks on a quest to find the god stones and awaken her twin sister, Ui.
At the start of the series, Kyouko is portrayed as selfish and naive but gradually becomes more friendly. She is known as the Time Stranger and wields the "Time Scorpion Cane," which allows her to travel through time and stop it.
Kyouko's real father is Chronos, the god of time, who was too weak to raise her. He asked the King of Earth to let Kyouko inhabit Ui's body and be raised until she turned 16. This makes Kyouko the future time queen.
When Kyouko awakens Ui, Ui's consciousness returns to her own body, causing Kyouko to lose her physical form and everyone to forget about her. Sakataki remembers her and helps others recall her as well. He travels to the end of time, Kyouko's true home. There, Chronos tries to kill Sakataki, but Kyouko intervenes. Chronos then declares that Kyouko is still a child and needs to grow up. As a result, he allows her to live on Earth without a body. The King lends his wife's (Kiyu, Ui's mother) body to Kyouko. Eventually, Kyouko and Sakataki get married, though Kyouko continues to write letters to Chronos.
