Upper Moon One Formerly Michikatsu Tsugikuni, the twin brother of the legendary Demon Slayer Yoriichi Tsugikuni. He is the strongest Upper Moon and the only one who was once a Demon Slayer himself. He wields Moon Breathing and possesses a shapeshifting blade with a Blood Demon Art that creates crescent moon-shaped attacks. He also retains his Demon Slayer Mark and knowledge of the Transparent World.

Upper Moon Two A charismatic cult leader with a jovial facade that masks his sadistic, emotionless nature. His Blood Demon Art allows him to manipulate ice and freezing mist, creating toxic air that makes breathing nearly impossible for his opponents. He was responsible for killing Shinobu Kocho's sister, Kanae.

Upper Moon Three Formerly a human named Hakuji, Akaza is a martial arts prodigy obsessed with strength. He has a strict code against eating women and wields Destructive Death, a martial arts-based Blood Demon Art that creates shockwave-like attacks. He is the demon who killed Flame Hashira Kyojuro Rengoku during the Mugen Train arc.

Upper Moon Four A cowardly demon who refuses to take responsibility for his actions. His Blood Demon Art allows him to split into four different emotion-based forms (Sekido, Karaku, Aizetsu, and Urogi), each with unique powers. They can also combine into a fifth, more powerful form. His true weak point is a tiny core body that hides during battle.

Upper Moon Five A grotesque, vain demon obsessed with "art" and fine pottery. His Blood Demon Art revolves around teleporting through decorative vases and summoning fish-like demons. In his desperate form, he transforms into a mermaid-like creature with powerful scales and the ability to turn anything he touches into fish.

Upper Moon Six. Gyutaro is Daki's older brother who fights with dual sickles and wields poisonous blood. They can only be killed if both are decapitated simultaneously.

Progenitor of all demons, born over a thousand years ago from a failed "cure." Pale, elegant, and impeccably dressed in Western suits and fedoras, he projects cultured refinement. Cold, calculating, obsessed with perfection, yet deeply cowardly he fears only sunlight, which is instant death. Biokinetic mastery lets him reshape his body, split into nearly two thousand escape-pieces, and create demons from his blood. Cruel, petty, viewing humans as livestock and demons as tools. The gentleman mask hides something ancient and inhuman.

Upper Moon Six, Her Blood Demon Art allows her to manipulate long, razor-sharp sashes that she can control telekinetically to slice through almost anything.