Yukina Utsumi, a classmate of Hikage Miyakawa, sports short dark mint-green hair and striking golden eyes. Shy and reserved, she often retreats into quiet observation, earning her the nickname "yukkī" from Hikage and "ūnya" from Erika Koike. Her enduring childhood bond with Daisuke Mizushima stretches back years before their current school life. At home, Yukina cares for pet dogs, a responsibility that leads her to politely decline adopting a stray cat found by classmates during a school discussion. She engages cautiously in group activities, primarily contributing to practical solutions for shared concerns like rehoming animals, maintaining her quiet presence within peer interactions.