Nene Yashiro attends Kamome Academy as a first-year high school student, continuing from middle school. She joined the gardening club, developing skills in growing vegetables and plants. Her interests in cooking, sewing, and gardening were cultivated partly to appeal to romantic interests, though these efforts often ended in rejection due to comments about her physical appearance, particularly her ankles, mockingly compared to daikon radishes. Her family appears in school album photos but has minimal direct interaction documented in her daily life. She resides in an apartment near a local playground and cares for pet hamsters, including one named Black Canyon and another referred to as White Inferno in certain contexts. Physically, Nene possesses waist-length hair transitioning from light cream to teal-green at the tips, styled with baby bangs and secured by dark brown magatama hair accessories resembling horns. Her large eyes are magenta with orange accents. She wears the Kamome Gakuen uniform: a cream-colored sailor dress with deep magenta lining, brown accents, and a skull brooch above the collar bow. Unlike most students, she pairs this with dark brown tights featuring small half-moon patterns near the ankles. Her design incorporates symbolic elements: the magatama accessories reference spiritual connections and foreshadow her role in supernatural events, while the moon motifs on her tights subtly allude to themes of life, death, and romantic associations in Japanese culture. The skull brooch remains consistently present across transformations, reinforcing her identity. Her personality blends earnest optimism with persistent insecurities. She exhibits kindness and naivete, frequently leading her into dangerous supernatural situations. A self-described hopeless romantic, she initially craved shallow validation through romantic relationships, falling easily for aesthetically pleasing boys like Teru Minamoto. This desire drove her reckless use of supernatural matchmaking methods, resulting in ingesting a mermaid scale that cursed her to transform into a betta fish upon water contact. The curse was mitigated when Hanako ingested another scale, binding their fates and confining her transformations to full submersion or scale appearances when wet. Over time, her motivations shifted from seeking romance to valuing genuine connections, particularly with Hanako. Insecurities about her ankles and perceived lack of femininity remain, though she develops greater self-respect and assertiveness. She expresses emotions openly and acts impulsively to protect others, sometimes neglecting her own well-being. Nene's abilities stem from supernatural interactions. She naturally sees apparitions, later revealed as a consequence of her shortened lifespan tying her closer to the Far Shore. She transforms partially or fully into a fish when exposed to water due to the mermaid curse. Her scales occasionally detach, serving as valuable supernatural currency. She wields the unique capacity to alter rumors about Kamome Academy's supernaturals, influencing their powers and behaviors. This ability, possibly linked to her status as a kannagi (shrine maiden figure), proves crucial in resolving supernatural conflicts. She also destroys yorishiro—objects tethering supernaturals to the world—triggering visions of the associated memories upon contact. Her relationships form core aspects of her development. With Hanako, their bond began as a contract after he shared her mermaid curse. Initially adversarial, it evolves into deep mutual trust and affection. She shifts from addressing him formally ("Hanako-san") to familiarly ("Hanako-kun") and later acknowledges romantic feelings for him. Their connection spans timelines: she interacts with his past self, Amane Yugi, during time-travel events, where he implies she is his ideal type. Four kisses and multiple confessions occur, though Hanako's ghostly status complicates their relationship. Kou Minamoto starts as an exorcist targeting Hanako but becomes a close ally. Kou develops unreciprocated romantic feelings for her, though their dynamic settles into a supportive, platonic partnership. Akane Aoi is her long-term best friend, though their closeness strains as Nene's supernatural engagements increase. Akane views her as a fellow victim of supernatural manipulation. Teru Minamoto, Kou's older brother, is an initial crush figure who shows polite but detached kindness toward her. Tsukasa Yugi, Hanako's twin brother, elicits fear and confusion from Nene due to his volatile and dangerous behavior. In the "After-School Hanako-kun" spin-off, Nene engages in lighter, episodic activities. She brainstorms ways to make her toilet-cleaning duties enjoyable, participates in supernatural games like Kokkuri-san, and experiences dream sequences where she transforms into a Mokke. One story involves her consulting peers about recurring nightmares, gathering accounts of supernatural dreams. Another depicts her temporary transformation into a Mokke, leading her to interact with Elder Mokke and learn hidden truths about the supernatural world. These vignettes emphasize her curiosity, adaptability, and persistence in navigating both mundane and bizarre school life. Key events shape her journey. Early on, her wish for romance backfires with the mermaid curse, binding her to Hanako. Destroying yorishiro for supernaturals like Tsuchigomori exposes her to Hanako's human past. Later, she discovers her lifespan is limited to approximately one year, intensifying her urgency to resolve supernatural threats. During the School Festival arc, Tsukasa kidnaps her to force yorishiro destruction; she resists, knowing completion would kill her. Mechanical owls de-age her to a toddler during this conflict. She encounters alternate timelines: one where Hanako lived to become a teacher (initially appealing until revealing his darker fate), and a future vision where she is possessed by Tsukasa and kills friends. She attempts to alter fate using a stolen hourglass but fails, reinforcing her determination to protect others despite despair. Her story culminated in a heroic sacrifice alongside Aoi in one timeline, enabling Akane to time-travel and prevent their deaths.