Hina is a fair-skinned young female with short, grass-green hair and light olive eyes. She often ties her hair into a ponytail on the left side of her head. Due to her youthful appearance, she is often mistaken for a first year rather than a second year.
Hina possesses a bright, cheerful disposition, and for the most part carefree and always works at her own pace. While she may appear unreliable, she possess a strong sense of responsibility, is very hardworking and does her best in everything, seeing things through to the end. Once she has decided on a certain thing, she stubbornly pursues her goals, making her impossible to stop. She is easily swayed by her emotions and quite a bit of a crybaby.
Hina is unfamiliar with Earth customs such as Hina Matsuri (Girls' Day), which implies that she was probably born and/or raised on the Moon. Not much is known about her family as well.
Hina looks up to Haru, her male counterpart, and likes him very much, seeing him as her type of male, pointing out his kindness. She can also become quite shy whenever she talks about Haru. Haru, on the other hand, notes Hina's comforting presence, and sees her as his younger sister.
- Her given name, Hina (ひな), could come from the kanji character "雛" (hina) which means "a small bird/chick" or "green" in the sense that one is not fully developed or mature.
- Her surname, Momosaki (桃崎), literally translates to "peach (fruit) cape".