Nadeko Sengoku, Tsukihi Araragi's childhood friend since elementary school, was raised in an environment prioritizing cuteness and surface perfection. This sheltered upbringing cultivated a passive personality; she presented herself as childish and obedient, relying on her appearance and perceived innocence to avoid responsibility or deeper connections. Her use of third-person self-reference and simplistic language indicated stunted emotional growth. She habitually hid behind long bangs and wore baggy clothing. During middle school, classmate Sunshi Sajou confessed to her. After Nadeko rejected him, citing her interest in Koyomi Araragi ("Koyomi-onii-chan"), both Sunshi and classmate Nakuna independently cursed her using jagirinawa charms obtained from Deishuu Kaiki. Her paranoia led her to perform incomplete snake sacrifice rituals at North Shirahebi Shrine, inadvertently activating the curses. Two invisible snakes coiled around her, causing physical harm. Koyomi intervened, battling the curses and breaking limbs, solidifying Nadeko's dependence on him for salvation. Nadeko harbored a longstanding, unrequited romantic fixation on Koyomi, using it as a shield against other relationships and maintaining a victim complex to avoid accountability. Occasional provocative behavior around him, like wearing revealing swimwear or inviting him over, stemmed from preserving her delusional romantic narrative, not genuine confidence. A turning point occurred when Ougi Oshino confronted her avoidance. Nadeko then hallucinated a serpent entity named Kuchinawa pressuring her to atone for killing snakes. As class representative tasked with resolving escalating classroom tensions—a role she resented—her protective forelocks were cut off by Tsukihi Araragi. Unable to hide her expressions, she suffered a psychological breakdown: screaming at her teacher and classmates, revealing suppressed self-loathing and resentment. In this destabilized state, she ingested a talisman containing Kuchinawa's remains at Koyomi's house, transforming into a snake god. This granted divine powers, including control over snake-hair and destructive capabilities sufficient to level Naoetsu Town. As a deity, she abandoned her shy persona for a cynical, violent demeanor, planning to kill Koyomi to eternally preserve her unrequited love fantasy. Deishuu Kaiki later intervened, exposing Nadeko's secret passion for drawing manga—a dream concealed in her closet for years. He convinced her humanity offered limitless potential for reinvention compared to a static apparition existence. Nadeko relinquished her godhood, embraced her artistic aspirations, cut her hair short, abandoned her cutesy affectations, and pursued manga professionally, eventually serializing three works. This marked her departure from dependence on Koyomi and her victim mentality. In later arcs, Nadeko exhibited a blunt, tomboyish personality, using masculine speech patterns and displaying crude mannerisms. She openly regretted her past immaturity and dependence, reflecting ongoing self-reinvention. Though her connection to Tsukihi remained, she no longer relied on the Araragi family for emotional validation.