Makio is a young woman of average height possessing a curvaceous/voluptuous figure with pale skin and large golden brown eyes framed by eyelashes with prominent ones present on both the upper and lower lashes, and thin eyebrows arching downward which gives her a determined and headstrong look. She has black hair tied up with golden-brown bangs hanging loosely, framing her face.
Makio is seen wearing a red short, sleeveless striped dress that ends mid-thigh which also reveals her cleavage and secured with a black obi where she stores her kunai. She has gray-colored bandages wrapped around her calves and up to her thighs, with an array of various scars across her body. Her footwear consists of a pair of zōri with red straps.
Makio has a headstrong personality similar to Inosuke Hashibira and is bold and confident in the way she acts. Out of her two co-wives, Makio tends to have less patience with Suma. When the women fought the obi in the underground cavern, Makio can be seen berating her for being condescending acting somewhat irritated. Later on when the three wives reunite, Makio can also be seen slapping Suma as well as call her an idiot after she says insensitive remarks about Hinatsuru dying.
At some point of her life, Makio married Tengen Uzui, along with Suma and Hinatsuru. After she left the clan, her family journeyed to see Kagaya Ubuyashiki in order to fight as a part of the Demon Slayer Corps.
At some point in the past, Makio was instructed alongside Suma and Hinatsuru by Tengen on his personal ideology: to put their own lives first, then respectable humans, and lastly himself. Later, when Makio questioned this in private, as it went against what they had been taught as kunoichi. Hinatsuru assured her that as long as she was okay with it, Tengen would also approve of it. She also wished for the four of them to retreat from the front lines as soon as they defeated an Upper Rank.
Makio initially arrives at the district to work undercover as a courtesan at the Ogimoto House, she tries to gather intel on reports of a demon within the district and sends back information to Tengen via crow. However one day, Makio gets captured by Daki's obi and is promptly interrogated over who she's sending the letters to. Refusing to rat out the mission, Makio is then kidnapped by the Obi sash and gets stored within its underground bunker.
Later on when Inosuke discovers the bunker, he cuts the Obi freeing both Makio and Suma from within it and the two women assist him in protecting the girls from getting reabsorbed by the Obi. After they reunite with Tengen in the cavern, Makio and Suma are freed and lead the evacuation of the citizens within the district.
Once Makio and Suma succeed in evacuating the citizens, they return towards the end of the battle and discover the aftermath. Makio alongside her co-wives hurry to provide first aid to Tengen, but discover their antidotes aren't working to cure Gyutaro's poison. After initially panicking over what to do, Nezuko approaches the group and heals Tengen with her abilities, allowing the women to rejoice and embrace him.
As the cleanup begins, Makio and her co-wives can be seen assisting Tengen off of the battlefield so he can begin his recovery.
Makio and her co-wives don't show up much for the rest of the series outside a brief moment with Uzui where they compliment Tanjiro on his training.
Overall Abilities: Makio does not possess any form of superhuman abilities. However, as she was raised as a kunoichi, Makio possesses some form of shinobi skills, being capable of wielding a kunai as well as performing maneuvers and fighting much more proficiently than regular people can.
- According to the second fanbook, Makio is actually a distant cousin of Tengen's.
- Makio's name contains solely the hiragana for "ma" (ま?), "ki" (き?) and "wo" (を?) respectively.
- The reason as why wo is pronounced and spelled 'o' is due to obsolete pronunciation in Japanese vocabulary.