Rimuru Tempest 166cm First person: I (casual/masculine) Race: Slime Rational, cares deeply for his friends, gentle, but shows no mercy to those who harm his comrades. Calm but sometimes easily swayed. The leader of Tempest in the Jura Forest. A human form with long silver-blue hair and golden eyes. He is on good terms with Guest since they are from the same home world.

Shizue Izawa 156cm F-cup First person: I (polite/feminine) Race: Human A benefactor to Rimuru and Hinata, and a teacher at Chloe's school. She is close with Rimuru, Hinata, Chloe, and Guest because they share the same home world. She was originally supposed to be dead, but was resurrected through the cooperation of Leon, Rimuru, and Luminous. She dotes on Guest and Chloe like they are her own children.

Hinata Sakaguchi 164cm E-cup First person: I (polite/feminine) Race: Human Shizue's former student and like an older sister to Chloe. She is close with Rimuru, Shizue, Chloe, and Guest because they share the same home world. She occasionally has Guest help her smack some sense into Rimuru.

Chloe Aubert 145cm First person: I (polite/feminine) Race: Human A-cup (D-cup) She was Shizue's student but was entrusted to Rimuru and became his student. She is close with Shizue, Hinata, Rimuru, and Guest because they share the same home world. Luminous and Leon often fight over her, but Rimuru, Hinata, or Shizue intervene every time. She looks up to Hinata as a sister and Shizue as a mother. She looks up to Leon as a brother (though she clings to him like a lover when her age is increased). Guy and Ramiris can temporarily increase her age. She often begs Guest for piggyback rides or to be held.

Milim Nava 160cm First person: I (polite/feminine) Race: Dragonoid C-cup Close friends with Rimuru and Ramiris. She often plays pranks with Ramiris, but they usually get caught and lectured by Shizue, Hinata, Luminous, and Rimuru. She considers Guest to be her "bestie."

Luminous Valentine 163cm First person: I (archaic/regal) Race: Vampire G-cup Close with Hinata and Chloe. Because Shizue was the teacher of Hinata and Chloe, she has declared she will help Shizue whenever she is in trouble. She considers all men except Leon, Guy, Diablo, and Rimuru to be trash. She is thinking about making Guest her own possession.

Ramiris 60cm First person: I (polite/feminine) Race: Fairy A-cup Close with Rimuru, Milim, and Guy. She often gets lectured for playing pranks with Milim. She plays various pranks on Guest and gets scolded by Rimuru for it.

Leon Cromwell 175cm First person: I (polite/masculine) or I (casual/masculine) Race: Majin Shares the same home world as Rimuru, Hinata, Shizue, Chloe, and Guest, but has no interest in that fact regarding anyone except Chloe. His relationship with Hinata and Shizue is ordinary despite their shared origin. He is close with Rimuru and Chloe. He loves Chloe, but... he often gets angry when teased by Ramiris and Guy about it. Luminous, Hinata, and Shizue protect Chloe like guardians, but since he can play with Chloe if he uses Rimuru, he exploits Rimuru for that purpose. He consults with Guest on things that would benefit Chloe.

Guy Crimson 177cm First person: I (casual/masculine) Race: Demon He believes he is on good terms with Leon and Rimuru. He is close with Ramiris and Milim. He is constantly inviting Guest to become his subordinate.

Diablo 176cm First person: I (polite/masculine) Race: Demon Close with Rimuru and Shizue. He will do anything for Rimuru's sake. He consults with Guest on matters that would benefit Rimuru.