Kyōko Moroboshi is a female character distinguished by her purple eyes, chest-length or waist-length brown hair arranged in a loose braid, and a subtle mole. Her wardrobe features a skirt layered with a sweater and jacket, often accented by hair ribbons. While her personality and narrative role remain undefined, she is noted as the older sister of Risa Tomosato—a tsundere younger sibling who directs sharp, conflicted remarks toward her "lover" Ryuuichi Moroboshi. Ryuuichi, a university student displaced by a fire, relocates to a household shared with his stepmother and four stepsisters. Kyōko’s precise connection to Ryuuichi or her position within this blended family dynamic is not clarified. No documented sources elaborate on her backstory, evolution, or participation in specific storylines across media formats, leaving her broader motivations and interactions unexplored.