Born February 17, 2122, Yukie Kariya is a former classmate and one of the few survivors from Michio Hino and Yumiko Toomi's class. She becomes a New United Nations agent, retaining conflicted feelings toward Tatsumiya Island and desiring recognition from an unspecified person, reflecting her idealism. During a Festum assault on the island, Yukie manages student evacuations, directing them to shelters and confirming others' safety at Alvis when concerns emerge about missing individuals. She maintains a connection with Kouzou Minashiro, though Soushi Minashiro's return limits her access to the household. Selected as test pilot for the black Salvator-model Fafner Mark Nicht—which utilizes the core of the sunken Mark Vier and is overseen by Jonathan Mitsuhiro Bartland—Yukie is assimilated during testing by the disguised Festum, Idun. This assimilation forces her to witness the Neo UN base's destruction and Mitsuhiro's death, through which Idun comprehends human anger. Yukie's ultimate fate remains unconfirmed. The Mark Nicht, originally intended for her, is later piloted by Misao Kurusu and Soushi Minashiro.