Koyuki

was a beautiful young woman who saved young Miroku's life seven years ago and died protecting children from the war.

History
Koyuki found Miroku lost in a snowy area seven years prior, and she saved his life.

During the story
Miroku encountered a woman who was identical to Koyuki and she took him back to her home, because she claimed that she had already birthed his child. Miroku was shocked to find many children living in her home, and he began to take care of all of them.

Sango and the others eventually find where they have gone, and noticed that the children Miroku had been caring for weren't children at all, but were balls of snow; they deduced that he must have had a spell put on him. Soon Inuyasha broke into the home and Koyuki unleashed a snow beast on him; Inuyasha managed to momentarily get away from it and finds Miroku and snaps him out of the spell.

Miroku's friends work together to destroy the snow demon, and they freed Koyuki's spirit from the demon in the process. It was revealed that Koyuki was the soul of a woman who had lost her life because of the war. After her death, she took in the spirits of children who also died in the war. At some point afterward, the Yuki-on'na took over her spirit.

Trivia

 * Koyuki's story is similar to the Princess in mist: Both were human women that died under tragic circumstances. Their spirits were possessed by yōkai and used their bodies as disguises in order to lure in men. Both of the yōkai that possessed them tried to lure Miroku at one point. Miroku willingly succumbed to them in order to free the women's spirit.
 * Her seiyū, Yūko Minaguchi, also voiced Hazuki from Rumiko Takahashi's anthology series .
 * Koyuki was inspired by the story of the Yuki-on'na, a type of yōkai who appears before men in the form of a ghostly woman with snow-white skin and garments should they be lost in the snowy mountains. In some stories, the Yuki-on'na is involved in an inter-species marriage, giving birth to a child to the man that she had saved. The latter detail is seen when Koyuki shows that she has already "bore" Miroku's children. In other stories, the yuki-onna appears a second time to the man she just saved, in a form eerily similar to the initial encounter. Unlike the actual Yuki-on'na in the episode, Miroku encountered the actual Koyuki first and then encountered her doppelganger.

Koyuki Koyuki Koyuki 小雪