Shione Sudo is the vice-president of the student council at the prestigious Beatrice-wielding academy. She is the younger sister of the student council president, Maya Sudo. Her most defining feature is her daily extravagant and complicated hairstyle, incorporating elements like hair drills, curls, and ribbons, often defying gravity for a distinctive look. These elaborate styles are so familiar academy-wide that she becomes unrecognizable with her hair down, surprising her brother Maya, who expresses joy at discovering he has such a cute sister.

She possesses a mischievous personality and actively schemes alongside student council members like Mitsuki Fujita and Yoko Kirishima. Shione exhibits deep respect and admiration for her brother Maya, addressing him with the formal honorific "sama." Their dynamic includes playful rivalry, evident during events like a hot springs trip where delivering shampoo escalated into a competitive mission involving battle plans and booby traps.

As a student council officer, she participates in the group's activities, which often involve observing or interfering in the lives of students Mamoru Yoshimura and Ayako Takasu, frequently leading to comedic confrontations with Ayako. She wears the standard academy uniform.