Koyuki

Koyuki was a fair-skinned young woman of small stature and slender build. She had large pink eyes that lightened toward the lower rim, with white flower-shaped pupils, framed by parted bangs and soft strands curving past her ears.

Her black hair was arranged in a traditional updo and adorned with a comb and three snowflake hairpins. She typically wore a circle-patterned kimono fading from pink to blue, decorated with vines and snowflakes and tied with a black obi.

Koyuki was kind, gentle, and caring. At her first meeting with Hakuji she set aside her own suffering to ask whether he was hurt after seeing his injuries. Once she recovered, she became bright and cheerful, working happily around the dojo and blushing fiercely when her father teased her about her feelings for him.

For much of her life her long illness weighed on her, and the suicide of her mother together with her father's quiet resignation left her convinced she would never heal. Though she needed constant help, she disliked being so much of a burden and urged Hakuji to take time for himself. His simple faith that she would live to see another year stayed with her always.

Koyuki was born frail and chronically ill. Her mother drowned herself rather than watch her child die, leaving Keizo to scrape together a living. He later brought home Hakuji, a banished criminal he had bested, and made him her caretaker so the two could grow close.

The arrogant heir of a neighboring dojo became infatuated with her but could not understand her illness, once forcing her outside during an attack and abandoning her in panic, after which Hakuji found and saved her. In time she recovered, and when her father offered Hakuji his dojo and revealed her feelings, the two became engaged. Enraged, the rival heir's faction poisoned the dojo's well, killing Koyuki at sixteen and her father hours later. Grief drove Hakuji to slaughter the dojo and accept Muzan's offer to become a demon. A century later, during Akaza's battle in the Infinity Castle, Koyuki's spirit reaches him, helps him reclaim his humanity, and welcomes him home as their souls pass on together.