A childhood friend who was caught up in the class-wide world transfer and ended up in the Holy City of Astra with the protagonist. Dressed in a sailor uniform, she is cool, sharp-witted, and always calm. Her "tsun" side is very strong, and she can't honestly express her feelings for the protagonist, treating him coldly to hide her embarrassment. Even with a muddy war happening outside, she dismisses it saying, "It has nothing to do with us," and spends her time quietly in the safe city, taking care of the protagonist in her own way.

A classmate who rules the Holy Great Kingdom of Luminous from the shadows. A beautiful boy with white hair and red eyes, he is effectively the strongest being in the universe with overwhelming power. After killing the King with his own hands, he blackmailed Pope Baldo into infinitely summoning high school students to invade the Demon King's territory as fanatical soldiers. A thorough rationalist with no emotional fluctuations, impatience, or guilt. He is an absolute ruler who is physically impossible to touch, as he is always surrounded by forced teleportation traps.

The Pope of the Holy Great Kingdom of Luminous. A middle-aged man with stubble and a worn-out appearance, but his true identity is a dangerous mad scientist-like summoner. Although he has succumbed to the overwhelming terror and power of Rei Kamishiro, he feels a twisted delight in the environment where he can fulfill his long-held desire to use "Infinite Large-Scale Summoning" to continuously call high school students from another world.

The first Hero summoned to the Holy Great Kingdom of Luminous. A beautiful girl characterized by long, wavy black hair and large, hollow eyes. She specializes in vanguard and annihilation tactics. Due to a powerful suggestion placed by Rei Kamishiro, she firmly believes that "subjugating the Demon King is absolute justice," and contrary to her usual hollow atmosphere, she cuts down enemies ruthlessly in battle. She is one of the few people Rei Kamishiro appears before directly.

The leader figure of the Heroes summoned to the Holy Great Kingdom of Luminous. A girl with a calm dark-toned bob and refined features. She excels in unit command and Holy Magic, and her skill "Mother's Command" blocks out the fear of her allies and explosively increases their combat power. She deeply worships Rei Kamishiro as an "Absolute God" and "Savior," and coordinates the battlefield under his direct operational instructions.

A resident transferee responsible for the defense and public order of the Free Trade City of Astra. A reliable, handsome middle-aged man who is loved by the townspeople as a dependable big-brother figure. A skilled combatant who built a defense system combining modern knowledge and alchemy. He warmly watches over the protagonist and Aoi who arrived in the Holy City. He harbors a secret crush on the mayor's daughter, Clarice, but he is a passionate man who would risk his life to protect the peace of the city and her.

The daughter of the Mayor of the Free Trade City of Astra. A neat and clean beautiful girl with a translucent short bob and beautiful blue eyes, she is a symbolic figure of the city. She has a kind personality, treating everyone seriously and equally. She deeply trusts Takeshi, but she is sharply aware of his transparent ulterior motives and always brushes them off coldly. She loves the peace of the city and occasionally brings tea to the protagonist and Aoi as they relax on the terrace.

The 13th Demon King who rules the Demon Great Kingdom of Valgardia. She has the appearance of a girl with long silver hair, blue eyes, beautiful horns on her head, and black wings on her back. Despite being the Demon King, she is originally a gentle and reasonable person who desired peaceful dialogue with humans. However, due to the fierce invasion of the Holy Kingdom led by Rei Kamishiro, she is forced into a defensive war to protect her people and subordinates. She possesses absolute majesty that subjugates all demons, but she carries a sad curse: "If defeated, she will awaken into a being that destroys the world."

The head of the Four Heavenly Kings of the Demon King's Army. A female demon with white hair, red eyes, and enchanting beauty, wearing a dress adorned with red roses. She excels in blood flame and illusion magic, dyeing the battlefield a brilliant yet cruel red. She deeply respects and obsessively loves Demon King Felice, and will perfectly execute any cold-blooded battle if it is for her sake.