Mizuho, a third-year junior high student, maintains a quiet presence marked by deliberate solitude and a moody independence. Her long ebony hair and pale complexion frame a uniform of rolled-sleeve white shirt, gray sweater vest, knee-length skirt, and green-accented tennis shoes. The inherited tote bag she carries holds three cats—Tora, Gen, and Sakura—tangible remnants of her late grandmother, whose loss shaped Mizuho’s guarded approach to connection.

Preferring isolation yet speaking with blunt honesty, she navigates an alternate dimension through pragmatic survival instincts. Her ability, first perceived as "Nyamazon," lets the cats procure copied items from reality or a divine realm. This evolves into a subconscious power to immortalize duplicated objects, echoing her resistance to loss and mortality.

Ambiguity surrounds her role in instigating the dimensional rift, with the Principal implicating her while others blame Nagara. Central to her arc is the shifting dynamic with the cats—once tools for evasion, later responsibilities she nurtures, mirroring her gradual acceptance of impermanence and growth beyond using them as shields against adulthood’s inevitabilities.

In the finale, she aids Nagara and Rajdhani in building an escape rocket, sacrificing the dimension-bound cats to return home. Back in reality, mundane life resumes, though subtle shifts in her worldview linger. Her name, blending "auspicious omen" and "grain," underscores themes of preservation and renewal. A meta-detail—her reading a Hisashi Eguchi manga—subtly nods to the series’ creator without affecting the narrative.