Nanami Hisami, nicknamed Nanamin, is the 13-year-old youngest member of the idol group Wake Up, Girls! Her image color is purple and her image animal is the wolf. She has shoulder-length brown hair, typically styled with bangs and tied into a ponytail using a ribbon, and dark almond brown eyes.

Confident and prideful, Nanami presents a self-assured, approachable demeanor. She harbors a strong ambition to succeed as an idol, driven by rigorous practice in singing, acting, and piano, with the ultimate goal of performing at the Hikarizuka Theater. A pivotal moment reinforcing her dedication occurs during an overnight trip to Kesennuma, where she learns about fellow member Mayu Shimada's past struggles and resolves to fully commit to the group.

Throughout her journey, Nanami evolves from a self-focused individual to a more team-oriented member. She occasionally masks nervousness with outward confidence, using this front to motivate others and uphold high standards within the group. In *Wake Up, Girls! New Chapter*, she advocates to live in the group dormitory instead of completing high school at home, prioritizing her idol career and bonds with the group over personal convenience. This decision reflects her willingness to sacrifice for collective growth, though she remains vocal in urging fellow members to maximize their potential.

Her surname, Hisami, combines the characters for "long time" (久) and "sea" (海). Her given name, Nanami, blends "vegetables/greens" (菜) and "beautiful" (美).