胡桃沢 鈴姫

She is a junior with a strong sense of justice and is the head of the school's general security department and is also involved in many special activities (a general term for activities in which students provide labor for the school).

She is strong-willed and competitive, and her emotions are easily expressed on her face. Once she gets her mind set on something, she takes action in a straight line. She tends to involve the people around her, mainly Yuu Sena.

She is the signboard girl of “Shiro no Koshika-tei,” a rival restaurant of “Sunny Side,” and sees Natsumi as her rival. She also has a hard time with Shinichiro, who works with Natsumi, so her impression of him is that he is a rival of Natsumi.