Chizuru Aizawa, eldest of the Aizawa siblings, co-manages the Lemon Beach House with her sister Eiko and brother Takeru. Her long indigo hair mirrors her eyes, framed by forehead bangs and often half-lidded, though they snap open to expose a piercing gaze when provoked. Beneath her composed exterior lies a fiercely protective streak, unleashing startling physical prowess—shattering tentacles bare-handed, sensing unseen movement—rooted in an undisclosed military past.

Orphaned early, she shoulders familial responsibility with quiet resolve, balancing patience toward the protagonist’s mischief with shrewd pragmatism, channeling their quirks to boost the restaurant. Childhood friend Goro’s lingering affection goes unreciprocated, her focus anchored to her siblings’ well-being.

A clandestine competitive streak surfaces in arcade rivalries, where she reclaims dominance within days of defeat. Privately sensitive about her weight, a detail others tactfully avoid, she masks her identity as Noh Mask Rider Hannya during beach events, intervening covertly in volleyball matches or performances.

Hints of a fractured psyche linger—gentle nurturer one moment, erupting into calculated ferocity the next—suggesting unresolved trauma beneath her yangire duality. While her life before the restaurant remains shrouded, her present is defined by unwavering loyalty to family, veiled strength, and the quiet theater of secrets she guards.