Kuina is a tall slim young woman who is always seen wearing a bikini swimsuit (as part of the regulations of the Beach), or a bikini top with hugging navy jeans that have many embedded silver beadings, and open-toed thick black sandals. She has long black dreadlocked hair pulled back in a ponytail, and she is often depicted with a fake cigarette in her mouth or in her hands.
Kuina has an easy-going and casual demeanor, she gets along with everyone, including Chishiya. Throughout the series, she is shown to care for the surrounding people, and ready to stand up for those she thinks are doing the right thing. From her reflections on her past, it is revealed that she is fiercely independent and has a strong desire to survive, especially due to her attachment to her sick mother.
Kuina is a transgender woman. Born as the only son to a family of martial artists, she was trained by her father in various fighting techniques in a dojo. However, Kuina did not have the disposition for martial arts and was often unable to finish a fight or land the final blow, which resulted in heavy abuse from her father. When she realized she liked herself wearing makeup by putting on a lipstick, her father got furious and threw all the cosmetics away. After Kuina decided to leave home, he told her to never return, even though her mother did not wish to lose her child.
Having changed her gender, Kuina started working as a sales clerk, and then at some point she found out that her mother was in hospital, so Kuina went to visit her. Her mother recognized her despite a drastically different appearance and called her beautiful, which made Kuina very happy, as it was the first time her family truly accepted her. Kuina then dedicated her time to taking care of her mother until the day she was transported to the Borderlands.