Description
At age seven, Nanoka Kiba survived a sinkhole disaster at Five Line Shopping Street that killed her parents. Clinically dead and covered in blood, she revived inexplicably. Her fragmented memories recall being pulled from the wreckage into a fiery hellscape where she encountered a monstrous creature with a decapitated head. Orphaned, she was raised by her grandfather, whose lifespan was unnaturally extended solely to care for her—later revealed as manipulation by the demon Byōki to ensure her development as a suitable vessel.

Nanoka discovers she can travel between the modern Reiwa era and Japan's Taisho era (1923) by passing through the abandoned Five Line Shopping Street. On her first documented journey, she meets Mao, an onmyōji who initially mistakes her for an ayakashi. This encounter reveals the blood covering her after the accident belonged to Byōki, cursing her like Mao. This shared curse allows her to wield Mao's sword, Hagunsei, which normally requires Byōki's blood. She later acquires Akanemaru, another sword that drains its user's blood.

The curse grants Nanoka enhanced physical abilities, including accelerated healing and strength. When accessing these powers, her pupils narrow into cat-like slits and turn red. For years, her grandfather's maid, Uozumi, administered a pungent green drink supposedly to fortify her health, but actually to suppress her demonic energy and hide her from Byōki. Uozumi is later revealed as a shikigami sent by Mao to protect her.

Nanoka exhibits curiosity, determination, and bravery. Initially fearful in combat, she gains confidence through experiences in the Taisho era. She actively investigates historical events linked to her curse, often enlisting her classmate Shiraha for research. Her relationship with Mao evolves from distrust to deep reliance and hinted romantic feelings, solidified by their shared mission to confront Byōki and unravel the curse. She also forms bonds with Mao's shikigami assistant, Otoya, viewing him as dependable.

Physically, she has short brown hair and light brown eyes, typically wearing her school uniform. Her surname "Kiba" (黄葉) means "yellow leaves" or "autumn colors," while "Nanoka" (菜花) refers to the rapeseed flower, symbolizing resilience in Japanese culture.