Yasuna Kamiizumi, a reserved high school student, navigates life marked by an unusual physiological condition: her inability to perceive male faces, which appear obscured by a gray haze. This lifelong challenge in the manga stems from birth, while the anime attributes it to childhood trauma involving her father. Her parents’ growing absence deepened her isolation, fostering self-reliance.

Her solitude shifts when she meets Hazumu Osaragi, a classmate whose face she sees clearly due to Hazumu’s inherent female identity. Yasuna’s emerging romantic feelings clash with her fear of losing this connection, leading her to reject Hazumu’s initial confession. After an alien accident transforms Hazumu into a girl, Yasuna confesses, her anxiety eased by Hazumu’s new identity and her own preference for same-gender relationships.

Adaptations diverge in her journey: the manga portrays proactive pursuit of Hazumu post-transformation, with Yasuna organizing gatherings and demanding exclusivity. The anime emphasizes initial avoidance, requiring Hazumu’s persistence to mend their bond. The OVA offers a bittersweet arc—her vision worsens, prompting a fleeting romance with Hazumu that dissolves when her sight returns, steering her toward independence.

Involvement in the music club, where she plays the flute, softens her aloofness. Her rooftop practice near Hazumu’s garden mirrors their deepening bond. Though reserved, Yasuna exhibits tenacity in love, yet fears of loss linger. Rivalry with Tomari Kurusu underscores her possessiveness and craving for emotional stability.

The condition’s adaptation-specific nuances—lifelong in the manga, temporarily extending to females in the anime—reflect her struggle with identity and acceptance. Her evolution traces a path from solitude to cautious self-assurance, adapting to shifting dynamics while balancing vulnerability and resolve.