My-HiME
Yukino appears as the secretary of the Fuuka Student Council and Haruka Suzushiro's best friend and confidant. She is in the same class as Mai Tokiha and Yuuichi Tate. She is frequently seen with her laptop computer and occasionally runs the communications network of the Executive Council. An introvert, Yukino frequently corrects Haruka's mispronounced or misspelled words as and attempts to calm the hot-headed Haruka down during crises. Yukino has been friends with Haruka since they were small children, and was often defended by Haruka when she was unable to defend herself from bullying. As such she feels great loyalty towards Haruka and often accompanies her during her (sometimes ill-planned) attempts to protect the school.
Yukino is revealed to be one of the 12 HiME after a vampire-like Orphan sent by the SEARRS foundation begins to attack girls on campus when she is contacted by the school's headmaster Mashiro Kazahana, who warns that Haruka may become a target if the Orphan attacks continue. Yukino then uses her CHILD, Diana, to survey the school and learn of the location of the captured Natsuki Kuga, which she sends to Mai in an anonymous text message.
When the SEARRS foundation invades the school Yukino uses her powers for reconnaissance to help her fellow HiME. However, she falls under a great deal of emotional stress as the rules of the HiME festival and the cost of losing are revealed and tensions between the HiME escalate. Later, believing that Haruka is in danger, she is psychologically manipulated by Ishigami the art teacher and nearly attacks Mai before stopping herself. However, Mikoto arrives and attacks Diana believing Mai to in danger until Mai herself intervenes. The relationship between the two girls is eventually reconciled as Yukino uses Diana's power of illusion to mask a battle between the HiME and tries to help locate Mai's brother Takumi Tokiha.
Eventually, Yukino locates Student Council President Shizuru Fujino where she is hiding with Natsuki, and observes Shizuru disrobing and lying down next to Natsuki and later stealing a kiss from the sleeping Natsuki while hiding in the bushes with Haruka, whose shocked reaction gives them away. After Haruka confronts Shizuru for her "disgusting" infatuation with Natsuki despite Yukino's attempts to calm her, Shizuru retaliates and kills Diana, and by extension Haruka, her Most Important Person. Despite this, Haruka manages to head-butt Shizuru before tossing her council badge at Yukino to reassure her and disappearing.
Yukino is reunited with Haruka when Mashiro resurrects the defeated HiME and their CHILDs, and at the end of the series Yukino is seen at the graduation with Haruka.
Read more about this topic: Yukino Kikukawa