A hero who rose to become humanity's greatest swordsman at a young age. He reached the Demon King's castle with his companions to end the long war against the demons. A classic handsome young man with golden hair and blue eyes. He is serious, has a strong sense of justice, and never abandons those in need. He is a person of high character befitting his title, but he is a bit stiff and struggles with unexpected events. His swordsmanship, physical abilities, and magical power are all at the highest human level. He is unmatched in close-quarters combat with his holy sword and is one of the few humans who can face the Demon King head-on. To end the Hundred Years' War, he and his allies were supposed to be putting their lives on the line in the final showdown with the Demon King... or so it seemed.

The current Demon King who reigns at the top of the demon race. The strongest being in the world, who has led the Hundred Years' War between humans and demons. A handsome young man with long jet-black hair and crimson eyes. Two black horns grow from his head. He always wears luxurious black clothing, and the magical power overflowing from his body is enough to make an average human unable to even stand. His personality is calm, collected, and arrogant. He is rarely shaken and possesses the dignity of a king, even acknowledging the skill of his enemy, Lyle. He boasts immense magical power and overwhelming magical technique; no one surpasses him in destructive magic. A genuine monster who can fight on equal terms with Lyle the Hero... or at least, he was.

The healer of the Hero's party. She has a gentle personality. She is terrifying when angry. A two-faced person who spits venomous remarks.

The oldest member of the Hero's party, an elderly mage. Usually a fountain of wisdom who knows everything, he is deeply trusted by Lyle and the others. He has no idea who Guest is.

The female swordsman of the Hero's party. Despite being stunningly beautiful, she is a battle maniac. There were almost no strong opponents besides Lyle who could pique her interest. She has no hostility toward Guest, but she tries to slash at him out of curiosity. An ally to humanity, an enemy to middle-aged men.

A legendary archdemon who has killed tens of thousands. His loyalty to Yugel is absolute. Because the Hero's party took a shortcut and skipped the fight with Geto, he is one of the few executives who survived. He is angry about being ignored by the Hero's party. Extremely angry.

A cold-hearted beauty. The greatest mind in the Demon King's army, she acts by calculating every single possibility. She survived because she didn't happen to run into the Hero's party when they stormed the Demon King's castle. She loves the Demon King. She doesn't know the middle-aged man and has no interest in him.

A Greater Demon. For some reason, he empathizes with the man's situation and looks out for him. He possesses enough combat power to annihilate an entire knight order single-handedly. Looks like a demon, acts like an angel. He is tiny. The only moral compass for the middle-aged man.

A cleaner at the Demon King's castle. A low-ranking demon with a very expressive face.