Ikuko Shiratori is a 17-year-old high school student whose unexpected arrival in the second season impacts the Watanuki sisters. She maintains a refined, ladylike outward demeanor, yet her true nature is notably spacey and absent-minded. An unexpected turn of events leads her to live with the Watanuki family, where she naturally becomes part of their daily life. Undisclosed complex family circumstances inform her character beneath her usual behavior. She possesses unconventional tastes, including a passion for Scandinavian metal music, often wearing band t-shirts at home. These avant-garde preferences sometimes cause friction with the youngest sister, Mitsuki Watanuki, who finds them irritating. Her presence introduces new dynamics and excitement into the Watanuki household, contributing to unfolding events within their family and neighborhood.