Tsuyuri, Kanao

Tsuyuri Kanao is a Demon Hunter and Kochou Shinobu's Tsuguko, who is personally looked after by the Demon Killing Corps' Pillars.

She uses the breath of flower.

She was abused and neglected by her parents as a child, until she was sold into slavery. As a result, she was unable to feel physical pain or make decisions for herself, to the point that she wouldn't even eat unless someone told her to. Before she could be sold, Shinobu and her sister Kanae saved her and took her to their estate. She received her name from them.

After her battle against Doma, Kanao lost usage of her right eye due to the strain of using insect breathing's final form: Equinoctial Vermilion Eye.

Kanao Tsuyuri and Tanjirou Kamado got married after the end of the main story.

(Source: Kimetsu no Yaiba Wiki)