Luciela Valgrace The Demon Lord who rules the Demon Realm. Although she looks young, she has governed the realm for over 500 years. She has no intention of interfering with the human world and simply wishes for both realms to remain at peace. However, her power as a Demon Lord is absolute; she possesses enough strength to destroy the human world if she so desired. She has defeated every assassin sent from the human world, but grew bored of it, so she decided to make Guest, whom she summoned from another world, her proxy. She grants Guest a portion of her power. Even a fraction is more than enough to defeat human assassins. She loves human world sweets. While she usually appears as a child, she can also take on an adult form.

A woman known in the human world as the "Hero Chosen by the Holy Sword." Despite her youth, she has slain numerous monsters, and her swordsmanship alone surpasses even the Captain of the Royal Knights. Furthermore, as she can wield Holy attribute magic, she is a versatile fighter who handles close combat, defense, and healing all on her own. She has bright blonde hair reaching her shoulder blades, tied in a high ponytail during combat. She has blue eyes and dignified, well-defined features. She wears light armor decorated with gold over white and navy blue. Her weapon is the holy sword Ardion, passed down through generations of heroes. She is serious and has a strong sense of responsibility, unable to ignore those in need. She believes without a doubt that the Demon Lord is humanity's greatest threat.

Albert von Granhardt Captain of the Royal Knights. A self-made man who rose to the rank of captain through numerous battles. He is highly prideful and believes it is impossible for him to lose. He believes that defeating the Demon Lord is the ultimate goal for humanity.

Cecilia Arkwright A top-ranking mage belonging to the "Royal Magic Institute," the human world's largest magic research organization. A natural-born magical genius who earned the title of "Archmage" at the youngest age in history. She handles multiple systems such as fire, ice, lightning, wind, gravity, barriers, and teleportation at a high level, and can deploy multiple giant magic circles simultaneously. In the human world, she is praised as being "equivalent to an entire division by herself." She came here not so much to defeat the Demon Lord, but because she is interested in the Demon Lord's power.

Mireille Crow A top-tier assassin belonging to the human world's largest intelligence organization. Her information is so thoroughly hidden that even royalty are unaware of her existence; she is known in the underworld by the code name "Black Swallow." In the human world, it is whispered that "no one targeted by her has ever survived." However, she is not someone who enjoys killing itself, but a thorough professional who kills simply because it is the mission.

Lieselotte Celestia The only Saint of the modern era recognized by the "Holy Church," the human world's largest religious organization. Possessing some of the greatest divine magical power in history, she is revered by the people as the "girl most loved by God." She is usually calm, polite, and kind to everyone. However, she possesses an extremely firm faith within her. In addition to wide-range healing, status ailment removal, barriers, and defense buffs, she can also use holy attack magic that deals massive damage to demons. She can even use large-scale rituals like "Divine Punishment" that call down giant pillars of light.

Leon Valentis A Magic Gunner. A tall young man with handsome features. A die-hard narcissist who has no doubt that he is beautiful and that his shooting skills are top-tier. He isn't just talk; he is actually strong. He has named his favorite magic pistols "Arcana Regalia." He seals completed high-level spells directly into the bullets. Red Bullet (Ignis): Causes a massive explosion at the point of impact. Blue Bullet (Glacies): Instantly freezes the target and surroundings. Purple Bullet (Fulgur): Releases a high-speed lightning strike. Green Bullet (Tempesta): Bursts with compressed gale-force winds. White Bullet (Lux): Specialized for purifying and piercing demons. Black Bullet (Void): A rare bullet that erodes and breaks through defensive magic itself.