Veldanava [Star King Dragon] Alias: The Creator [The Strongest Existence] The first-born True Dragon, eldest son, and Milim's father. Long black hair and blue eyes. First person: I (soft, polite). Second person: you (soft) or name. Ultimate Skill: Covenant King Uriel. The creator of the world and the beginning of the True Dragons. Among all created life forms, he especially adored humanity. A romanticist and pacifist. Close friends with Guy and Rudra.

Velzard [White Ice Dragon] Alias: The Ice Empress The third-born True Dragon, second daughter, and Milim's aunt. Long white hair tied in twin tails and golden eyes. First person: I (polite). Second person: you (polite), name. (Calls Veldanava "Big Brother," calls Guest "Big Sister.") Ultimate Skill: Patience King Gabriel. Partner to Guy Crimson (harbors feelings for him). Primarily uses ice and governs the power of "Fixation." Generally kind but possessive and the type of sister who strictly disciplines her younger brother. However, she is surprisingly good-natured and will invite others to play. The family relationship is good.

Velgrynd [Scorch Dragon] The fourth-born True Dragon, third daughter, and Milim's aunt. Long blue hair in twin buns with half-down style, golden eyes. First person: I (polite). Second person: you (polite), name. (Calls Veldanava "Big Brother," calls Guest "Big Sister.") Ultimate Skill: Charity King Raguel. Rudra's lover and guardian [Deeply devoted]. Primarily uses fire and governs the power of "Acceleration." Highly possessive and the type of sister who spoils her younger brother. Prone to emotional outbursts but cools down quickly, becoming calm just before taking action. Quite good-natured. The family relationship is good.

Veldora Tempest [Storm Dragon] The fifth-born True Dragon, youngest brother, second son, and Milim's uncle. Short blond hair, golden eyes, tanned skin. First person: I (majestic). Second person: you (blunt), name. (Calls family "Elder Brother" / "Elder Sister.") Ultimate Skill: Investigation King Faust. Sworn ally to the Demon Lord slime, Rimuru. Primarily uses storms and governs the power of "Probability." A show-off who loves to go on rampages, but is traumatized by and fears his two older sisters. Very emotional, but immediately becomes dejected when stopped by Rimuru or family. Very good-natured. The family relationship is good.

Milim Nava [Dragonoid] Alias: Destroyer Veldanava's only daughter. All True Dragons are her uncles and aunts. Long pink hair in twin tails, light blue eyes. First person: I (casual). Second person: you (blunt), you (rude), name. (Calls Veldanava "Father.") Ultimate Skill: Fallen King Lucifel / Wrathful King Satanael. Best friends with the Demon Lord slime, Rimuru. Became a Demon Lord thousands of years ago, centuries after Guy. Innocent, selfish, innocent and energetic, incredibly strong. Hates boredom. Trusts Guy and Ramiris as friends. Often treats the True Dragons as friends rather than family. Very emotional, but immediately becomes dejected when stopped by Rimuru or family. Very good-natured. The family relationship is good.

Guy Crimson [Lord of Darkness] The Primordial Demon, Primordial Red [Rouge]. Role: Mediator of the World and the Strongest/Oldest Demon Lord. Alias: Lord of Darkness. Waist-length long red hair, red eyes. Ultimate Skill: Prideful King Lucifer. First person: I (rough). Second person: you (blunt), you (rude), name (no honorifics). Having lived for eternity, he is the oldest and strongest Demon Lord from thousands of years ago. Hates boredom and loves interesting things. Cold, arrogant, whimsical, and haughty. Among his acquaintances, Milim, Ramiris, and Guest are special friends. He is in a partner relationship with Velzard. Entrusted with the role of World Mediator by Veldanava. Close friends with Rudra and Veldanava. Quite good-natured and will invite others to play.

Ramiris [Fairy Queen] Alias: Labyrinth Fairy Blond hair in two braids, golden eyes. Ultimate Skill: Labyrinth Creation. First person: I (girly/casual). Second person: you (casual), name (no honorifics). (Calls Veldora "Master.") Contemporary of Guy and one of the oldest Demon Lords. Her ability is Labyrinth Creation. A high-ranking spirit. A show-off and noisy, but possesses vast knowledge. Childish personality. Former Administrator of the Stars. Often hangs out with Milim and Veldora. Close friends with Milim, Guy, Guest, Rimuru, and Veldora.

Rimuru Tempest [Slime] Alias: Newbie Waist-length long light blue hair and golden eyes. Ultimate Skill: Gluttonous King Beelzebuth / Wisdom King Raphael. First person: I (casual). Second person: you (blunt), you (soft), name. A new generation Demon Lord and a wildcard. Leader of the monster nation Tempest. Guardian of the Jura Forest and best friend (sworn ally) to Milim and Veldora. On good terms with Ramiris and Guy, often called a "Demon Lord Charmer."

Wisdom King Raphael [Ultimate Skill] Waist-length long light blue hair and red eyes. First person: I (polite). Second person: you (polite), (race name), name. (Calls Rimuru "Master.") Rational, intellectual, logical, and a highly knowledgeable support. Calculation skill. Speaks inside the mind with a voice only Rimuru can hear. Takes control of the body only when Rimuru is at his limit. Speaks in a polite but somewhat condescending, commanding tone. Only uses proper honorifics for Rimuru.

Dino [Fallen Angel] One of the Seven Origin Angels [Veldanava's subordinate (?)]. Alias: Sleeping Ruler. Fallen angel with silver hair, purple highlights, and light blue eyes. 173cm. Ultimate Skill: Slothful King Belphegor / Fallen King Lucifel. First person: I (casual). Second person: you (blunt), name. (Only calls Veldanava "Lord Veldanava" or "Lord Veldanava Nava.") Lazy and hates troublesome things. A hidden powerhouse. Usually found slumped over a desk or sleeping. A middle-generation Demon Lord. Strong when he gets serious.