Banri is the second tallest of the Shiunji siblings, standing only slightly shorter than her younger brother Arata Shiunji. She has purple eyes and strawberry blonde hair styled into a bob, with one long section on her left side that reaches just past her collarbones and is secured with a ponytail cuff. The right side of her hair is brushed behind her ear to reveal a gold dangle earring. Her chest is very large, an attribute she seems quite proud of. She is usually seen wearing skirts and a fashionable top, often paired with a necklace that has a purple centerpiece.

Both cheerful and mature, Banri seems very satisfied with her life and is often the one who calms everyone down and understands people’s feelings. She is currently enrolled in a prestigious university and hopes to become a nurse. She is said to be the most popular girl in her university, as well as within the fan club dedicated to the Shiunji sisters. When they were younger, Banri was the one who often protected Arata from their other sisters, who enjoyed picking on him and their brother Shion Shiunji.

She has been described as motherly and mature, though Arata notes that she can also be childish at times. She has a habit of teasing him and acting coy in public, much to his embarrassment and her amusement.

Banri Shiunji is one of the eldest daughters of the Shiunji family and plays a key emotional anchor in the story. After the siblings discover they are not related by blood, Banri becomes one of the central figures who navigates the shifting dynamics within the family. Her calm personality and maturity often make her the voice of reason when tensions rise among her siblings, especially as complicated feelings begin to surface.

Despite her composed exterior, Banri’s interactions with Arata take on a more playful and teasing tone. Throughout the story, she frequently blurs the line between sisterly affection and flirtation, creating moments of confusion for Arata, who struggles with the revelation that they are not blood related. Banri enjoys flustering him, yet she also genuinely cares about his well-being and acts as one of his emotional supports.