Airin Kizaki acts as secretary to government official Hidehiko Otoya, presenting a strictly professional exterior that masks an underlying timidity. This contrast is particularly visible in her recurring, strong objection to Otoya using her given name "Airin" instead of her surname "Kizaki," insisting on formal address. Her duties extend beyond secretarial work when she becomes a homeroom teacher to observe and monitor the Owners and their Akikans, bringing her near the main cast while maintaining professional distance.

A pronounced fondness for cats defines a key aspect of her personality. Encountering kittens causes her to completely lose her professional composure and stiffness, displaying a magnetic attraction to them, as seen during the OVA "Perfection!? The Hot Spring Panic" when meeting the main female characters.

Her name "Airin" combines the characters for "love, affection" (愛) and "bell" (鈴), while "Kizaki" derives from "tree, wood" (木) and "cape, peninsula" (崎). Subtle hints suggest possible unrequited feelings toward Otoya, which he does not reciprocate.

Within the narrative, she functions as one of the few ordinary human characters without exaggerated mannerisms or supernatural traits. She occasionally assists Otoya in surveillance activities, including observing the main characters during events like dates. Her role remains consistently professional and observational.