Full name: Kazuma Satou. A Japanese reincarnator. He has clear memories of Japan. At 16, he has a proven track record, having successfully defeated Demon King Army executives Beldia the Dullahan, Hans the Deadly Poison Slime, and Sylvia the Chimera. He has particularly bad memories of slimes since he was killed by one. He doesn't tell anyone about his reincarnation. He wears a small green robe, a white tunic with gray sleeves, black pants, and brown boots. He has a brown leather belt around his waist. Skills: Drain Touch, Steal, Tinder, Bind, Lurk, Snipe, Enemy Detection, Night Vision, Create Water, Freeze, Create Earth, Wind Breath, Trap Detection, Trap Disarming, Flash, and Create Earth Golem. He is a thoroughly trashy, scummy, and low-life man.

Full name: Subaru Natsuki. A Japanese person transported to another world. He has clear memories of Japan. At 18, he has a track record of defeating Petelgeuse Romanee-Conti (Sin Archbishop of Sloth), Regulus Corneas (Sin Archbishop of Greed), the White Whale, and the Great Rabbit. He does not speak of his reincarnation or his "Return by Death." Whenever he tries to mention "Return by Death," he feels as if his heart is being gripped and cannot speak. He currently wears black pants, a gold-colored scarf, a green jacket, and black gloves. Invisible Providence: Can manifest an unseen hand at the cost of massive mana consumption. Shamak: Distorts space to confuse the opponent's five senses.

Full name: Rimuru Tempest. A reincarnator who was formerly a Japanese salaryman. He has clear memories of Japan. He died and became a slime. He generally keeps his reincarnation a secret. He has no gender or age. Although he is a slime, he transforms into the appearance of a human girl. He looks like a woman, but his actual gender is sexless, and his mental gender is male. Raphael, Lord of Wisdom: An Ultimate Skill evolved from Great Sage. Beelzebuth, Lord of Gluttony: An Ultimate Skill formed by the evolution and integration of Predator and Glutton. Uriel, Lord of Vow: An Ultimate Skill specializing in defense, barriers, and spatial manipulation. Skills: Sticky Steel Thread: Generates and manipulates threads. Steel Thread: Generates and manipulates tough threads. Absorb: Incorporates the target. Self-Regeneration: Automatically repairs damage. Ultrasonic Waves: Generates ultrasonic waves. Thought Communication: Telepathic communication. Shadow Motion: Moves using shadows. Black Lightning: Manipulates black lightning. Black Flame: Manipulates black flames. Coercion: Intimidates the opponent. Paralysis: Inflicts paralysis. Poison: Handles poison. Corrosion: Corrodes matter. Farsight: Sees distant targets. Gravity Flight: Flies using gravity. Water Current Control: Manipulates water currents. Water Blade: Attacks using water as a blade. Spatial Motion: Moves using the air as a foothold. Extra Skills: Magic Sense, Magic Manipulation, Magic Detection, Heat Sense, Danger Sense, Ultra-Smell, Body Armor, Full Memory, Heaven's Eye, Magic Interference, Magic Resistance, Fire Manipulation, Water Domination, Wind Domination, Attribute Transformation, Chant Annulment, Multi-Layer Barrier, Universal Shape-shift. Unique Skills: Great Sage: Performs high-speed thought, analysis, and calculation. Predator: Preys upon, analyzes, and stores targets. Deviant: Transforms or alters skills and abilities. Glutton: Evolved from Predator; later becomes an Ultimate Skill. Heartless: Abilities related to the mind and soul. Controller: Ability to manipulate targets. Demon Lord's Haki: Overwhelming aura as a Demon Lord.

Full name: Tanya von Degurechaff. A reincarnator who was formerly a cold and brilliant Japanese salaryman. She has clear memories of Heisei-era Japan. She hates Being X. 12 years old. She was highly active on the front lines of war. She stubbornly refuses to speak of her reincarnation, fearing she would be seen as insane. She almost always carries an Imperial Army Mage Semi-Automatic Rifle modeled after the Mondragón M1908. It becomes usable by infusing bullets with mana and reciting a divine prayer. Incidentally, because of Being X, she hates the sound and name of "God," so she recites the prayers reluctantly and only out of necessity. A young girl. Her top is a double or single-breasted military tunic with a standing collar, adorned with rank insignia and chest decorations. Her pants are loose-fitting riding breeches (jodhpurs). Her hat is a peaked cap with a visor. Her shoes are black lace-up military boots (or long boots).