Tamayo

Tamayo made a pact with Tanjiro: he would harvest the blood of the most dangerous demons (including those from the "Twelve Demon Moons"), and she would study it and find a way to reverse the transformation. She also studied the blood of her sister, Nezuko.
In the final battle, Tamayo, joining forces with Yushiro and Shinobu Kocho, created a drug that greatly weakened Muzan. Although she failed to kill him, her actions gave the fighters a fighting chance. Tamayo sacrificed herself to lure Muzan into a trap.
After Tamayo's death, Yushiro continued to live on, keeping her memory alive, and became an artist.

Tamayo is a powerful demon with unparalleled knowledge of medicine and demon physiology. She possesses virtually unlimited stamina and can manipulate her body to survive on minimal amounts of human blood.
Her signature skill is "Blood Demon Art." She releases her own blood, the scent of which can induce hallucinations or act as an elixir of truth, compelling those she speaks to to reveal hidden secrets.

When Tamayo was human, she was married and had children. Shortly before her transformation, she contracted a dangerous illness and desperately sought a cure. At that moment, Muzan appeared and offered to "cure" her by turning her into a demon. He didn't reveal the full consequences, and after her transformation, Tamayo, driven mad by hunger, killed her family and many others. She later sank into despair and began killing for blood, but eventually regained her sanity.
After approximately 200 years of studying demons, Tamayo met a terminally ill boy named Yushiro. She offered to become a demon to save his life, and he accepted. Yushiro became her assistant.
Tamayo's resolve to avenge her family was rekindled when she witnessed the power of Yoriichi Tsugikuni, who was close to killing Muzan.

Tamayo is a gentle, wise, and incredibly intelligent woman. She has dedicated much of her life to studying demons and their transformations, becoming one of the most knowledgeable characters in the series. Despite the hostility between humans and demons, she showed kindness to people and used her medical skills to help the wounded and sick.
She was staunchly against violence: instead of killing people for blood, Tamayo purchased it from voluntary donors. She also taught her assistant, Yushiro, to fight violence and often scolded him for his penchant for fighting. Tamayo was one of the few demons who were able to restore and retain their human emotions.
However, when confronted by Muzan Kibutsuji, she displayed cruelty and malice. Muzan noted that this vicious side was her original personality during her early years as a demon.

Tamayo is a beautiful woman with long, dark brown hair pulled back into a low ponytail with a flower clip. She has large, pupil-less eyes, smoky pale pink that fades to dark lavender, and bright red lips against her pale skin. She usually wears a dark purple kimono, decorated with wavy, pale purple tree branches and red flowers.