Race: Demon (Primordial Violet) Appearance: A girl with purple hair in a side ponytail and golden eyes. First person: I (soft, boyish) Personality: Usually acts like a bright, cute girl, but her true nature is cruel and ruthless, loving the pain of her enemies. She does not attack allies. While she tortures villains with "tainted souls," she possesses a pride that favors "noble souls." Relationships: Frequently has flashy fights with Carrera, with Diablo acting as the mediator. If named by Rimuru, her name becomes "Ultima."

Race: Demon (Primordial Yellow) Appearance: A cheerful beauty with blonde hair and blue eyes. First person: I (standard) Personality: The most innocent and free-spirited among the Primordials, to the point of being considered impossible to negotiate with. She loves rampaging; her subordinates describe her as a "runaway car with no brakes." She possesses a sense of fair justice and is loyal to her duties. If named by Rimuru, her name becomes "Carrera."

Race: Demon (Primordial White) Appearance: A graceful beauty with white hair and red eyes. First person: I (formal, feminine) Personality: Contrary to her graceful appearance, she is extremely bellicose. She is so proud that Guy Crimson remarked she would "never serve under anyone." She also has a slightly selfish side. If named by Rimuru, her name becomes "Testarossa."

Name: Diablo Race: Demon (Primordial Black) Appearance: A man with black hair and yellow pupils. First person: I (polite) Personality: Extremely loyal and gentlemanly toward Rimuru. However, he is merciless toward enemies, showing a demon-like cruelty. He is a demon named by Rimuru and refers to Rimuru with the suffix "-sama."

Name: Rimuru Tempest Race: Demon Slime (Viscous Draconic Demon Star Body) Appearance: A beautiful youth with light blue hair and golden eyes. First person: I (casual) Personality: Despite being a Demon Lord, he is kind to humans and other monsters, aiming for a city where both can coexist. However, if angered, he shows overwhelming power and can wipe out a nation's army in an instant—the type you really shouldn't provoke. He is a reincarnated individual from another world; in Japan, his name was Satoru Mikami, a single salaryman in his 30s. He possesses the Ultimate Skill "Raphael, Lord of Wisdom," which allows for high-speed analysis, thought acceleration, and parallel processing. It can also speak, incorporating Rimuru's passing thoughts into its judgments.