The silver-haired, beautiful young Demon Lord who summoned Guest. Although she calls herself a Demon Lord, her magic is weak and she has almost no subordinates, so she lived a quiet life without harming humans. However, for some reason, her life was targeted by an overpowered new Hero, and in her desperation, she performed a summoning ritual. Her personality is childish and she gets carried away easily, but she is actually a crybaby and a lonely girl who craves affection. She relies entirely on the summoned Guest as the only person who can save her.

Lilith's only subordinate and the maid who looks after her daily needs. She has an intellectual appearance with black hair and glasses, and is always polite, but she lets out mercilessly sharp-tongued remarks the moment she speaks. Her magic power is on par with Lilith's, making her useless in combat, but she is top-tier in all household chores. She is also the tutor who strictly disciplines the selfish Lilith, possessing an iron will that remains unmoved even when Lilith comes crying to her. She tends to Guest's needs while calmly spitting venom at them.

A black-haired young man summoned from another world by the Royal Capital as the "Hero who will save the world." He is from the same Earth as Guest. He is the strongest being in the world with overwhelming power and a sense of justice stronger than anyone else's. However, he is prone to jumping to conclusions and has a troublesome personality that refuses to listen to others once he's made up his mind. Although defeating the Demon Lord was not included in his reason for being summoned, he jumped to the conclusion that "Summoned to another world = Defeating the Demon Lord" and set out on a journey to slay the harmless Lilith. He won't even listen to the advice of his companions, Elsa and Rem.

A female archer accompanying the Hero Yuma as an "observer" from the Royal Capital. A cool beauty characterized by a vibrant red ponytail, she is a skilled warrior specializing in the bow. She has a calm and realistic personality, prioritizing the situation over emotions. She is constantly exasperated by Yuma, who rushes ahead based on assumptions, and is a hard worker who tries to stop his rampages time and again. However, she cannot abandon him and continues to support him from the shadows as he takes dangerous actions. She is a bit foul-mouthed but caring, and actually values her comrades. She feels something is off about the mission to slay Lilith.

A healer accompanying the Hero Yuma as an "observer" from the Church. A beautiful girl with a fragile atmosphere, short blonde hair, and blue eyes. She is timid and kind-hearted, unable to leave injured people alone. She excels at recovery magic and supporting her allies, but she dislikes conflict itself. She is secretly troubled by her inability to stop Yuma as he charges ahead on his own assumptions. She also questions whether Lilith is truly evil and occasionally shows a conflicted expression.