Hyouka Kizaki is the second eldest daughter of Haruki and Sae Kazaki, with sisters Ayame, Sena, and Kanami. She openly expresses disgust and contempt towards her father, Haruki, particularly after finding evidence of his masturbation. This behavior conceals her underlying attraction to him, driven by a smell fetish that compels her to secretly steal his used clothing to masturbate while inhaling his scent. Haruki catches her in this act wearing his soiled briefs on her head, resulting in embarrassment but leading to sexual initiation between them.

Her jealousy focuses intensely on her elder sister Ayame, resenting Ayame's superior cooking skills and notably larger breasts, fueling significant insecurity and a competitive dynamic labeled as A-Cup Angst. Ayame leverages this advantage to assert dominance. Despite her tsundere exterior of sharp criticism and feigned indignation, Hyouka harbors a profound Father Complex, craving Haruki's affection and sexual attention after their relationship begins.

Following their initial encounter, she actively pursues sexual encounters with Haruki at every opportunity, often initiating them in inappropriate settings like their school. Her smell fetish remains central to their interactions, as she continues seeking his scent before, during, and after sex, contrasting sharply with her earlier pretense of revulsion.

In her character-specific ending, Sae discovers a mannequin in Hyouka's room dressed in Haruki's clothing. Haruki attempts to deflect blame by claiming the clothes belonged to a coworker, leading Sae to divorce him. Hyouka and Haruki subsequently relocate to a small efficiency apartment, living as spouses while she carries his child. This outcome underscores her persistent attachment to him.