Saiko, Yuki

彩弧由貴

Yuki is the final product of the highly classified YLPER Project (an acronym for "Ylem perception," akin to ESPER, as stated in the manga), which sought to develop 'Esper weapons' via genetic manipulation. She appears to be one of four subjects, alongside Lisa, Hiroko, and Annie. Her main ability is precognition and clairvoyance. However, as Annie explains in the anime (episode XRP - 77), she also possesses the powers of the other three subjects. This means she can teleport objects (including herself and groups of people), generate force shields capable of reflecting or neutralizing various attacks, and cause explosions with her mind. All these abilities make her capable, as Toru confirms in the anime's final episode, of "changing the future with her own hands".
Rally Cheyenne found Yuki crying on the street and later recruited her for her immense psychic powers. Yuki serves as the team's 'mascot', dispatch officer, and Lebia's data processing assistant. Although Yuki sometimes acts a bit airheaded (she is only a teenager), she can display considerable courage when necessary.
Yuki operates a small coffee shop named Labyrinth, but it is more of a hobby than a business, as she is a full-time police officer. However, the lease states that as long as she runs it, she does not have to pay rent. (It is later revealed that this is because Toru Washio, her lifelong love, owns the building where she lives).
She met her love interest, Toru Washio, in 1997 following an encounter with a Lucifer Hawk and a magical coffee mill. He was 17 at the time, and she was 18. They met again after Yuki returned to her own time, 2027, with Toru having waited over thirty years for her.
Near the end of the anime, it is revealed that Toru was also responsible for founding Project YLPER. He had sold his soul to Nemesis so that he could see Yuki again. When he finally understood Ganossa's plans for Earth and Nemesis, he started the aforementioned project so that humans "had a chance to win over the Lucifer Hawks" (episode 26).