Tamayo takes the form of a beautiful woman with long, dark brown hair, parted in the center and worn braided back into a large, low bun, which is held in place by a floral hairpin. She has large, gentle eyes that do not possess pupils, only a haze of lavender that fades to dark purple the higher it goes, and notably red lips in contrast to her pale complexion.
Tamayo wore a dark purple kimono that was decorated with wavy pale purple tree branches and red flowers, and a cream-colored obi to secure it around her waist, as well as plain white socks and violet zōri sandals.
Before in her past, Tamayo wore her hair tied in a low ponytail and had stilted pupils.
Tamayo is a gentle, wise, and incredibly intelligent individual. Having devoted most of her life to researching the science behind Demons and Demon Transformation, she was one of the most knowledgeable people on the subject in the series. Despite the generally chaotic relationship between humankind and Demons, she showed a great deal of kindness towards humans. She made it apart of her mission to assist injured or sick individuals with her expansive medical knowledge — Tanjiro Kamado being among them. Tamayo had a strong preference against violence, instead of killing humans for their blood, she chose to buy blood from consenting donors to survive. She was adamant in teaching her assistant, Yushiro, against violence and often reprimanded him for his habit of hitting others. She was one of the few Demons who, in her later Demon life, was able to regain and retain her human emotions.
However, despite her usual kind, caring, and considerate disposition and personality, Tamayo has displayed a more cruel and vicious persona upon confronting Muzan. This was seen when she gleefully boasted to him that she'd successfully created a human-transforming drug and managed to inject it into him, and later, upon being devoured and eaten, reduced to mere cells inside his body, Tamayo again showed her cruel side as she revealed the real effects of her drugs. Muzan hinted that this vicious personality was Tamayo's original personality back in her earlier years as a Demon. She then slowly changed into the wise and considerate woman she is in the current day as time went by.
Despite this, as seen during the flashbacks hundreds of years before Muzan's meeting and battle with Yoriichi Tsugikuni, Tamayo was shown to have a more docile personality, a likely result of her realizing how impossible it was to defeat Muzan with her power to avenge her family. However, this changed upon her witnessing Yoriichi's strength and how close he came to killing Muzan, as Yoriichi noted that he saw a glint of hope in her once-deadpan eyes as she realized that he'd almost killed her former master, showing that, upon seeing Yoriichi's power, Tamayo's resolve to avenge her family was reignited.
Abilities and Powers
Though very little of Tamayo's abilities are seen, given that she was Muzan Kibutsuji's personal aid before the Twelve Kizuki were even formed and that he spared her after she attempted to kill him (something he sees as anathema) means she is both very old and very powerful.
- Medical Skills: Tamayo had displayed impressive skills in the fields of medicine and pharmaceuticals, possessing the skill to alter her own body so she could survive on only a small amount of human blood. She was also able to convert the terminally ill Yushiro into a Demon without Muzan's blood and is later able to reverse the process when treating the man they encountered during the Asakusa Arc. To further showcase her pharmaceutical skill, Tamayo was also able to assist Shinobu Kocho in saturating her body with deadly Wisteria poison without it so much as causing her the slightest illness; a tactic the Hashira would later use effectively against Upper Rank 2, Doma.
- Anti-Blood Demon Coagulant: Tamayo created this medicine to prevent a Demon's Blood Demon Art from progressing. Yushiro used this medicine to cure Zenitsu Agatsuma after his fight with Kaigaku.
- Anti-Kibutsuji Drug: It was later revealed that upon teaming up with Yushiro and Insect Hashira, Shinobu Kocho, Tamayo had successfully created a powerful, four-stage drug that could gravely weaken Muzan Kibutsuji. Once administered into him, its effects would be strong enough to significantly harm him despite his immense physical resistances and abilities. The first stage of the drug consisted of the same human-conversion stage that was included in the drug given to Nezuko Kamado.
- Aging Stage: The aging stage was the second stage of the drug's effects, included as a countermeasure if the human-conversion stage of the drug would fail, an idea proposed by Shinobu. Tamayo crafted the drug to be capable of aging its user at a rate of fifty years per minute. The drug successfully managed to internally age Muzan 9,000 years for three hours, severely deterring him in his battle as his body was forced to divide its power to fend off the drug's effects and fight the Demon Slayers at the same time.
- Division Prevention Stage: The third stage of the drug, activating after the aging stage. After witnessing Muzan's escape from Yoriichi Tsugikuni's grasp by dividing his body into 1,800 different pieces and escaping individually to reform at a later time, Tamayo proceeded to include a drug that would prevent him from splitting. Through this, his attempts to divide up his body into bits was unsuccessful, rendering him unable to escape.
- Cellular Destruction Stage: The fourth and final stage of Tamayo's drug was to be activated once the first three stages had finished taking effect. This stage began to destroy his body on a cellular level due to the incredibly potent effect of the first three stages of the drug, which heavily weakened Muzan's normally near-indestructible body. As a result of this final drug, Muzan begins to cough blood due to the internal damage wrought by the final stage, the effects of this stage also completely and utterly weakened Muzan to the point that his entire body felt heavy and unmovable, rendering him unable to move one of his arms and weakened him enough to the point that he was rendered unable to activate another technique, let it be his power or Blood Demon Art.
- Human Conversion Stage: Tamayo, with the assistance of Shinobu and Yushiro, was finally able to create a drug that reverts a Demon into a human, something that was thought to be impossible by the Demon Slayer Corps and the creator of the Demon race himself, Muzan Kibutsuji. The drug was used on Muzan, Nezuko, and Tanjiro, but only Nezuko and Tanjiro were able to revert to their human form while Muzan remained in his Demon form.
- Supernatural Blood: Tamayo's main ability is to draw her blood and cast various spells that enact various effects on her targets.
Blood Bewitchment (
- Scent of Illusory Blood: Visual Dream (
視 覚 夢 幻の 香Shikaku Mugen no Kō?) - A hallucination that hinders the vision of the affected by creating beautiful flower patterns around them.
- Magical Aroma of Daylight (
白 日の 魔 香Hakujitsu no Makō?) - Acts as a truth serum, causing brain function to decrease and will make the recipient confess their lies and not keep their secrets. It can be harmful to humans.
- Tamayo's name contains the kanji for "pearl" and "world".
- Tamayo was ranked 18th in the first character popularity poll, with 138 votes.
- Her Japanese voice actress, Maaya Sakamoto, is married to Obanai's Japanese voice actor, Kenichi Suzumura.
- Tamayo was at least 400 years old, as she lived during the same time as Yoriichi Tsugikuni.
- (To Tanjiro Kamado) "You still use... the term "person"... to refer to even a transformed demon. And you're trying to save him. Allow me, then, to lend you a hand."
- (To Muzan Kibutsuji) "Today... is... the day... you... will fall... into... hell..."
- (To Muzan Kibutsuji) "The drug... I used... turns you into a human... and... I'm not telling you. Why don't you try using all those useless brain cells you now have?"
- (To Muzan Kibutsuji) "Well, well. It looks like the death you've hated for so long is right before your eyes now."
- (To Muzan Kibutsuji) "I don't need to be stronger than you to kill you. I can just make you weaker. Just as you'll do whatever it takes to stay alive, I... No, we will do whatever it takes to kill you."