Tomari Kurusu anchors the narrative through her enduring childhood bond with Hazumu, forged in mutual defense and shared history since toddlerhood. She habitually shielded Hazumu from bullies targeting his delicate features and timid nature. A youthful jest saw Hazumu proposing to be her "bride," which she countered by asserting boys must be grooms—sparking a lighthearted vow that he’d assume that role eventually.

Physically distinctive, Tomari’s tall, athletic frame combines lean muscle with long limbs and a modest bust, contrasting Hazumu’s softer figure. Her reddish-purple eyes fluctuate in hue with her moods, paired with deep amber hair styled in slender twin tails. She favors functional, boyish attire—tees, shorts, sportswear—though sporadically dons casual dresses. School and athletic uniforms mirror her dynamic lifestyle, emphasizing ease of movement.

Her persona merges assertive leadership and guarded tenderness. Proactive and fiercely protective, she readily confronts threats but risks alienating sensitive peers like Yasuna with her frankness. Emotional transparency eludes her; vulnerabilities hide beneath a stoic facade. This duality fuels her evolving dynamic with Hazumu, transitioning from childhood fondness to disorientation after his gender shift.

Initially jarred by Hazumu’s transformation, Tomari battles envy as his bond with Yasuna deepens, yet stifles her turmoil to aid his adaptation. Tension crests upon mistaking Hazumu and Yasuna’s closeness, spurring her to impulsively kiss him. Gradually confronting her desires, she accepts her affection during a Christmas orchestrated by friends, later formalizing their union via OVA marriage.

A track star celebrated for sprinting prowess, Tomari earns the "prince" moniker for her androgynous allure, juxtaposing Hazumu and Yasuna’s femininity. Though she spurns conventional girlish pursuits, a festival sees her briefly don a yukata, hinting at sporadic versatility.

Family context remains sparse, with fleeting hints of a younger sibling and parents who disapprove offscreen of her gender nonconformity, underscoring her self-reliance amid societal expectations.

Her narrative arc weaves unwavering loyalty with introspective growth. From guarding Hazumu against intrusive media to mediating friend disputes, she navigates a path of tenacity and emotional maturation, culminating in embracing love without compromising her core identity.