Tamayo (珠たま世よ Tamayo) is a major supporting character of Demon Slayer: Kimetsu no Yaiba. She is a demon, a skilled doctor, and close ally of Tanjiro Kamado. She is physically 19, but chronologically 500. Being 4'11" in height, her Birthday on July 2nd. During the final confrontation between humanity and demons, Tamayo, along with Yushiro, joins forces with the Demon Slayer Corps to develop a drug that would aid in the defeat of Muzan Kibutsuji. Tamayo likes cleaniness, so dislikes messiness.