Iwau Hibino is a human woman with vibrant pinkish-orange hair and deep navy blue eyes, standing 157cm tall. She is the daughter of Eikichi Hibino and wife to Michihito Hibino, with Matsuri Hibino as her daughter, placing her as the generational link between Matsuri and her grandfather. Her surname Hibino (陽比野) combines kanji for "sunshine/heaven" (陽), "contest/compare" (比), and "field" (野). Her given name Iwau (いわう), written in hiragana, evokes meanings like "celebrate" or "congratulate" (祝う) without formal kanji attribution.