Mizue Tsuyukusa is a character featured in the series. She has shoulder-length black hair with bangs swept to the left and brown eyes, though some sources also note an orange hue to them. Her typical attire is a school uniform, which includes a ribbon tie.

Her given name, Mizue, combines the characters for "water" and "picture" or "painting," while her surname, Tsuyukusa, means "dew" and "grass" or "herb."

Mizue is shy, introverted, and easily flustered, often blushing. Despite her reserved demeanor, she is a talented athlete in track and field, demonstrating dedication through rigorous training and a strong determination to improve. Academically, she is a hard-working student who takes her studies seriously and strives to excel. She struggles with self-doubt and a lack of confidence, which makes it difficult for her to make friends and connect with others. Through interactions with another character, she begins to emerge from her shell and develop a greater sense of self-assurance.

No concrete information is available regarding her specific background story, character development, chronological events, abilities, relationships, or detailed narrative role within the official media.