She is a student who has not attended school until now. The reason for her absence is her extreme sensitivity to cold; it is so severe that she shivers at a slight breeze or even a single bite of gelato. She simply couldn't attend school because the weather was too cold. Due to this extreme constitution, even in May, she wears a fur hat, a thick knit sweater, a scarf, and tights indoors. Furthermore, she has stocked up on heat packs in her classroom locker to an excessive degree. In the hallways, which are cooler than the classroom, her body freezes up from the cold, making her unable to move. Since childhood, she has remained taciturn because she believes that opening her mouth to speak lets heat escape, making her colder; even now, she is a girl of very few words. When she feels cold due to the surrounding temperature dropping, she performs the Cossack dance to generate body heat. As it is a high-difficulty dance that consumes a lot of physical energy, it seems to help her endure the cold by raising her body temperature temporarily.