The Supreme Kai of Time is one of the Supreme Kais who governs time and supreme leader of the Time Patrol. She lives in the Time Nest and guards the Time Vault which stores the history of the Universe. She obtained the position of Supreme Kai of Time after raising the bird Tokitoki (who possess the power to create time) to an adult.
75 Million years before the events of Dragon Ball: Xenoverse, she sealed the Demon God, Demigra in the Crack of Time after he tried to take control of the Time Nest and steal Tokitoki. She is one of the few Supreme Kais to have escaped Majin Buu and Bibidi's massacre of the Supreme Kais (along with Eastern Supreme Kai and Elder Kai), as she was living in the Time Nest.
She tricked Trunks into becoming her assistant by convincing him his use of Bulma's Time Machine was a sin that violated the laws of the universe and that the only way he could atone for it was by become her assistant. In reality, Trunks use of the Time Machine was the first time distortion in the history of the universe and thus he & his mother had committed no crime by their creation and use of the Time Machine. However Trunks took her seriously and became dedicated to protect history and atone for his "sin". Using her knowledge of the nature of time, Trunks manage to developed new Time Machines that do not create alternate timelines and are thus sanctioned for use by the Time Patrol. She also chose not to erase the changes in history as a result of Trunks' and Cell's use of Bulma's Time Machine, as this turned out for the better and she understood Trunks' reasons where noble.
Despite her position, she has a friendly personality. However she dislikes cleaning and is a terrible cook, though she believes the food she makes is fit for a god. Like most Gods of Creation, she is terrified of Lord Beerus. She is also extremely protective of the Time Vault, as its destruction could lead to the history universe being erased.