Uehara Yui was a police detective from Nagano prefecture and subordinate of Yamato Kansuke. She grew up in the same village with Yamato in Nagano prefecture. After their childhood friend, popular village policeman and kyujitsu master Kuroto Kai died under mysterious circumstances, Uehara and Yamato decided to investigate the case together. When Yamato was critically injured in an unrelated case, resulting in a scarred eye and damaged leg, Uehara continued the investigation by herself after quitting the police force and marrying into one of the families suspected of murdering Kai. Despite spending a year in the household, the case remained unsolved until another series of mysterious murders occurred with her husband as the first victim. Conan and Heiji were called upon to solve these cases. Soon after their resolution, Uehara rejoined the police force. Uehara is friendly and considerate while Yamato has a harsh appearance and behavior. Despite hints suggesting that she may be in love with him, her professionalism has prevented any serious personal engagement, although Yamato seems not to object.