A 16-year-old girl from the moon, Kozue expresses her emotions easily and with clarity as she is honest about them. She wears her hair in twin side pigtails, making her seem younger than she is. In the flight attendant program, which she joined mostly because her friends were also enrolled in it, Kozue becomes good friends with Aoi, and by extension, Kouji and Ikumi. An honest girl, Kozue talks to Yuki without fear, despite his reputation. Kozue has a crush on Ikumi, and only stayed for the Dive Break because he was. She also seems to be somewhat spoiled, and often flaunts her relationship with Ikumi.