Kira Yukimura is a kitsune, the daughter of kitsune Noshiko Yukimura and Ken Yukimura, and Scott's second girlfriend. In Season 3B, Kira is the new girl at school, having moved to Beacon Hills from New York. Kira is initially portrayed as intellectual, quirky, sweet and looks to make friends in school, but has trouble fitting in because of her dad being the new history teacher who's prone to unintentionally embarrassing her. She is now a member of Scott's Pack. As a Kitsune, Kira is of the type Thunder, which gives her influence over electricity and her eyes glow a flaming orange.
At Season 3B's start, Kira displays a crush on Scott, which he reciprocates. In "Galvanize", Kira is revealed to be supernatural after mass murderer William Barrow kidnaps her and manifests an ability to absorb electricity after he attempts to kill her by electrocution. Scott witnesses this display and Kira is intrigued that Scott doesn't "run the other way" from her peculiar circumstances. In "Illuminated", it is shown that Kira gives off an aura that is shaped around her like a flaring armor in the shape of an bipedal fox that's visible to a werewolf's vision. Scott invites her to Danny's black light party and their interest in each other strengthens and later, she witnesses Scott and Derek fight the Oni in their werewolf forms. Consequently, Scott reveals the supernatural status of he, his Pack, everything to her. Kira eventually does research and theorizes she is a Kitsune, the trickster Fox, which is later confirmed by Derek. Kira later discovers further abilities; supernatural speed and agility, as well as a natural talent for swordplay. When her mother Noshiko displays similar talents, she discovers Noshiko is also a Kitsune and had summoned the Oni to Beacon Hills. In "The Fox and the Wolf", Kira confronts her parents, along with Scott. Kira is distrustful of her mom and is further baffled when Noshiko reveals she is actually 900 years old. Noshiko tells Kira her story of her time as an intern at Camp Oak Creek and her role in unleashing the Nogitsune. Noshiko asks Kira to trust her this once, telling her she is a Thunder kitsune and shows her how to use her talents to repair her shattered katana. Kira is told Noshiko's legacy is now hers when she passes her the sword. Kira comes to grips with her Kitsune nature, her capacity to fight and becomes part of Scott's Pack, wanting to help save Stiles and cure him. In "De-Void", still unable to face her parents after everything they've kept from her, Kira spends the night with Scott. They kiss. In "Insatiable", Kira along with Isaac and Allison go up against Noshiko and the Oni trying to dissuade her mother from outright killing the Nogitsune as the process could probably kill Stiles. Unfortunately, the Nogitsune takes control of the Oni and turns the demons against them and Allison is killed. In the Season 3 finale, Kira is told by her parents their move at this point has to be a divine move in order to stop the Nogitsune. Kira goes along with Scott, Stiles and Lydia to stop the Nogitsune at the school. She battles the Oni and then fatally stabs the Nogitsune running the demon's corporeal form through with the katana after Scott Bites him.
At the start of Season 4, Kira has her romance with Scott on hold because she wants to give Scott the time he needs to grieve for Allison. In "Muted", Kira shows an aptitude for lacrosse, joining the lacrosse team, and Scott decides to give in to his feelings for Kira, saying he's "not sorry", to her joy, sharing a deep kiss with her. When the Dead Pool goes out, assassins coming into town, Kira takes actions to protect herself and Noshiko as she and her mother are both on the hit list and Noshiko no longer possesses the power she had previously. In "Monstrous", Kira saves Brett Talbot and Lorilee Rohr of Satomi's Pack from a team of hunters-turned-assassins and fights to protect Satomi's Pack until the Dead Pool is shut down and the contracts are terminated. Scott and Kira finally go on their first date. They are attacked by Kate and her Berserker and are taken to La Iglesia. Kate has Scott converted into a new Berserker, and under the malevolent werejaguar's control, Kira is attacked by Scott. Hallucinating her mother and determined to save Scott, Kira breaks off a piece of obsidian in the temple and uses it to trigger her kitsune healing. She and Stiles save Scott when he's almost destroyed as a Berserker, as per Peter's plan. Kira keeps the obsidian shard when returning to Beacon Hills. Afterward, her father Ken has the shard reshaped into a shuriken and Noshiko presents her with the star, and Kira realizes the shuriken represents her first Kitsune Tail.