Nanami Miura, a 26-year-old personal trainer and osteopathic clinic employee residing near the Mutoh family, balances her profession with a passion for martial arts. She sports ochre hair tied in a ponytail, matching amber eyes, and a distinctive birthmark or mole. Her self-reliant nature shines when she confronts a truck driver attempting assault, deftly disarming him and later offering his recovered glasses to Haruo Koga to replace damaged ones.

Nanami shares a close, sisterly bond with Ayumu Mutoh, providing steadfast support during their trials. Her story reaches a tragic end as the group traverses a volatile mountain region. After venturing with Ayumu into a secluded area, Nanami collapses, succumbing to invisible toxic gases unleashed by seismic shifts—a danger foreshadowed by scattered bird carcasses. Her sudden death reverberates through the group, leaving Ayumu burdened by guilt and grief over her loss.