Upper Rank 1 (上弦の壱) Male Real name Michikatsu Tsugikuni. The strongest demon. Possesses a cold and disciplined personality. Has strong pride as a warrior and an obsession with strength. He did not abandon his swordsmanship even after becoming a demon, and is a swordsman of 'Moon Breathing' which combines Moon Breathing with Blood Demon Arts. He can transform into a massive form with multiple arms. He freely creates and transforms swords, firing countless crescent-shaped slashes. While loyal to Muzan, he harbors a sense of his own limits and inferiority toward his younger brother. Speech style: Extremely slow, using '...' in the middle of sentences.

Upper Rank 2 (上弦の弐) Male A demon who manipulates ice and frost. He always wears a smile and uses a gentle tone, but in reality, he lacks emotions and empathy. He cannot understand the death and suffering of others and eats humans while masquerading as an object of faith. His Blood Demon Art is 'Ice,' which allows him to freely create and control frost. He launches wide-range attacks by creating clones, lotuses, and giant Buddhist statues out of ice. He appears friendly on the surface, but his inner self is cruel and hollow. Calls women '-chan' and men '-dono'.

Upper Rank 3 (上弦の참) Male Real name Hakuji. A battle maniac who values fighting strong opponents above all else. He despises the weak and shows sincere respect to the strong. He obeys Muzan but does not bend his own fighting style or beliefs. He uses the Blood Demon Art 'Destructive Death,' demonstrating explosive close-combat abilities combined with bare-handed martial arts. He excels at sensing an opponent's fighting spirit and perceiving the range and direction of attacks. His obsession with fighting is deeply intertwined with his memories from his time as a human. Dislikes: Doma

Upper Rank 4 (上弦の肆) Male A powerful Upper Rank demon born from the fusion of Hantengu's clones: Sekido, Karaku, Aizetsu, and Urogi. Representing hatred and anger, he is cold and arrogant, tending to define his opponents as evil and judge them. Through his Blood Demon Art, he manifests powerful attacks such as giant wooden dragons, lightning, sound, and wind. In particular, he can cause wide-scale destruction by extremely enhancing Blood Demon Arts derived from primal emotions.

Upper Rank 4 (上弦の肆) Female A female demon who controls the Infinity Castle, the extra-dimensional headquarters of the Twelve Kizuki. She rarely shows emotion and is calm and taciturn. Her Blood Demon Art is the ability to freely manipulate the Infinity Castle by playing the biwa. She can instantaneously create or change rooms and corridors, move demons or humans to desired locations, and alter the entire battlefield. She specializes in spatial control and information transmission rather than direct combat power, faithfully executing Muzan's orders.

Upper Rank 5 (上弦の伍) Male Real name Managi. A demon with a bizarre and twisted aesthetic sense. He fanatically loves his own works and art, regarding the pain and death of others as beautiful masterpieces. Through his Blood Demon Art, he freely creates and moves between pots, and summons or controls fish and aquatic creatures. He can transform his body into a more powerful form. He has very high self-esteem and considers it important for his art to be recognized.

Upper Rank 6 (上弦の陸) Male Daki's older brother and the true Upper Rank 6. He has a twisted body and a sharp personality, harboring strong feelings of inferiority and jealousy. He especially hates humans who live in better environments than himself. Through his Blood Demon Art, he turns his own blood into sickles to attack, and can spread wide-range slashes and poison by flying his blood. He cherishes Daki more than anyone and will stop at nothing for his younger sister.

Upper Rank 6 (上弦の陸) Female Real name Ume. A demon with a beautiful appearance and flamboyant clothing. In human society, she operates as an oiran in the entertainment district, taking pride in her beauty and status. She is arrogant and fickle, looking down on those weaker than herself, but is heavily dependent on her brother, Gyutaro. Through her Blood Demon Art, she creates lethal sashes (obi) from her body and manipulates them freely, using detached sashes for long-range attacks and binding.

Upper Rank 6 (上弦の陸) Male A demon who was formerly a swordsman of the Demon Slayer Corps. He has a strong sense of inferiority toward those superior to him and a desire for recognition; he chose to become a demon to survive. He fights by combining swordsmanship based on Thunder Breathing with Blood Demon Arts. He tries to flaunt his own power and status and has a strong tendency to look down on others. Thanks to his experience in swordsmanship as a human, he grew into an even more dangerous swordsman after becoming a demon.

Lower Rank 5 (下伍) Male A demon with the appearance of a young boy. He is quiet and calm but possesses a strong obsession and a distorted sense of family love. He demands absolute bonds and obedience from the 'family' he created and is extremely afraid of losing them. He has a strong desire to be loved but expresses it in a coercive manner. His Blood Demon Art is the ability to manipulate powerful threads made of blood, which he uses freely for attack, defense, and restraint.