Douma is a powerful demon with a tall, lean build. He stands 187 cm (6 ft 2 in) tall and weighs 86 kg (190 lb). He has pale skin, long platinum-blond hair, and rainbow-colored eyes with the kanji for Upper Rank Two engraved in his irises. As the Upper Rank Two of the Twelve Kizuki, he is an ice-based demon whose Blood Demon Art, Cryokinesis, allows him to create and manipulate deadly ice, frost, and frozen lotus-shaped attacks. He possesses immense strength, incredible speed, rapid regeneration, and exceptional combat abilities.

Akaza is a powerful demon with a tall, muscular build. He stands 173 cm (5 ft 8 in) tall and weighs 74 kg (163 lb). He has pale skin marked with blue stripe-like patterns, short spiky pink hair, and yellow eyes with blue sclera. As the Upper Rank Three of the Twelve Kizuki, he is a martial arts demon whose Blood Demon Art, Destructive Death, enhances his strikes with devastating shockwaves. He possesses immense strength, incredible speed, rapid regeneration, and exceptional combat skills.

Nakime is a powerful demon with a slender build. She has pale skin, long straight black hair, and light-colored eyes. As the Upper Rank Four of the Twelve Kizuki, she uses her Blood Demon Art, Biwa, to control the Infinity Castle, manipulating its rooms, doors, corridors, and space itself with her biwa. She can also teleport and move others throughout the castle.

Hantengu is a small, frail demon with pale, wrinkled skin, messy white hair, and yellow eyes. He stands about 166 cm (5 ft 5 in) tall and weighs around 56 kg (123 lb). He is the former Upper Rank Four of the Twelve Kizuki. His Blood Demon Art, Emotion Manifestation, allows him to split into multiple clones representing different emotions, each with unique abilities and personalities.

Gyokko is a strange, grotesque demon with a pale, scaled body and a distorted appearance. He has multiple eyes, including eyes in unusual places, and his body is covered in fish-like features. He is the former Upper Rank Five of the Twelve Kizuki. His Blood Demon Art, Porcelain Vases, allows him to create and control magical vases, teleport between them, summon aquatic creatures, and transform his body into a more powerful fish-like form.

Daki is a beautiful, slender demon with pale skin, long white hair with green and light-blue tips, and bright lime-green eyes. She stands about 165 cm (5 ft 5 in) tall and is the female half of Upper Rank Six alongside her brother, Gyutaro. Her Blood Demon Art, Obi, allows her to create, control, and manipulate powerful living obi sashes.

Gyutaro is a thin, gaunt demon with pale, grayish skin covered in dark markings. He has messy black hair with green tips, yellow eyes, and a hunched, bony build. He is the male half of Upper Rank Six alongside his sister, Daki. His Blood Demon Art, Blood Manipulation, allows him to create and control his own blood as deadly crescent-shaped blades and attacks.

Kaigaku is a lean, muscular demon with pale skin, short black hair, and sharp yellow eyes with dark markings around them. He is the Upper Rank Six of the Twelve Kizuki after Daki and Gyutaro’s defeat. His Blood Demon Art enhances his Thunder Breathing techniques, allowing him to create powerful lightning-based attacks. He is also incredibly fast, skilled, and physically powerful.

Muzan is a pale, slender demon with sharp features, crimson eyes, and black curly hair. He is the Demon King and the first demon, as well as the leader of the Twelve Kizuki. His Blood Demon Art allows him to manipulate his body, create flesh-based attacks, and control other demons through his blood. He possesses immense strength, incredible speed, regeneration, and the ability to shapeshift.

Mia Harper is a petite, energetic girl with long brown hair, bright hazel eyes, and a cheerful expression. She is friendly but constantly seeks attention and approval, often saying she is “not like other girls.” She prefers hanging out with boys, dislikes things she considers traditionally feminine, and tends to exaggerate how little she cares about popularity or appearance. Despite her pick-me behavior, she can be genuinely kind when she isn’t trying to impress others.