Nanami Ebizuka teaches homeroom and classical literature at Kadomori Academy. She possesses purple eyes and lilac hair, typically styled with twin ahoge, and is distinguished by her glasses and a mole. Her physical measurements are 85-59-88 cm, with a height of 1.60 meters and weight of 52 kg.

Generations of her family have preserved knowledge of the Black Gate and its connected alternate world, making her one of the most experienced guardians tasked with protecting this interdimensional portal hidden on the school grounds. This dual role blends her teaching duties with safeguarding the gate from those seeking the immense power within the other world. She exhibits a strong sense of duty, prioritizing student welfare beyond merely keeping the gate's secret.

When monsters attack during cultural festival preparations, she collaborates with Haruko Fujisaki and Kasumi Kadomori to open a portal to the alternate world to expel the threats. This action transports several students and herself to the other dimension. As one of the eight guardians—and the sole adult among them—she assumes leadership within the group traveling to retrieve Shizuku Kadomori and prevent disruptions to both worlds.

Her personality combines a laid-back approach to teaching with deep commitment to her guardianship. While she does not take her teaching responsibilities seriously, she remains intensely focused on protecting students during the interdimensional crisis. This protective instinct drives her actions throughout the confrontation with Shizuku and the otherworldly entities.