Isaki Kudō, Chika Kudō’s paternal aunt, offers him shelter after his grandfather Gen’s death, residing in a sleek high-rise apartment that implies a well-paying yet unspecified profession. Her shoulder-length black hair and polished fashion sense contribute to a striking presence often remarked upon for its elegance. Brusque, fiery-tempered, and fiercely independent, she balances her blunt demeanor with subtle acts of care, offering direct advice or discreet support. Her dynamic with Chika intertwines teasing and discipline—leaving belongings strewn through their shared space or delivering light physical reprimands—while actively nudging him toward romantic pursuits with Satowa Hōzuki. Her bond with Suzuka Takinami, a Tokise High math teacher, traces back to a training camp where Suzuka taught her cooking. Former schoolmates, Isaki remains Suzuka’s junior, their camaraderie enduring beyond their academic years. Isaki anchors Chika during his turbulent adolescence, locating him after Gen’s funeral following a clash with his father and inviting him into her home. This choice reconnects Chika to Gen’s legacy via Tokise’s koto club. Later, she acknowledges his mutual feelings with Satowa, addressing the relationship’s nuances in a composed, candid conversation. Outside caregiving, Isaki savors sake evenings and oscillates between holiday overspending and marathon sleep sessions. Her name merges “clothing” (衣) and “blossom” (咲), while her surname, Kudō (久遠), signifies “enduring time” and “distance.”