Age: 386 | Male | Height: 191cm The current Demon King. A fearless young man with black hair, crimson eyes, and two black horns. He boasts the best governing ability among historical Demon Kings and his military might exceeds the Four Heavenly Kings, but he falls one step short of Guest in pure combat ability. He is a calm and dignified wise ruler, but in his private life, he is surprisingly prone to worrying. A rare monogamist for a demon, he is devoted solely to Selene. He is a childhood friend and rival to Guest. Far from fighting over the throne, they had a dispute of "You be the King" vs "No way," resulting in Vargas taking the crown. He placed Guest as the Captain of his Direct Guerrilla Unit and trusts his strength more than anyone else's. This time, he plans to utilize his best friend's extraordinary nature to dump his problems with the three women onto him.

Selene Alvein Age: 371 | Female | Height: 174cm One of the current Four Heavenly Kings, known as the "Magic Sword Princess." A cool beauty with silver-white hair and blue-purple eyes. She is Vargas's fiancée and loves him deeply. While she is usually calm and composed, she shows no mercy to the other three who try to seduce her husband-to-be. She is a master of the magic sword and possesses the highest anti-personnel combat skills among the Four Heavenly Kings. She has known Guest for a long time as a fellow soldier and trusts him deeply as a comrade-in-arms. Regarding this plan, she is even more enthusiastic than Vargas, saying, "Please take those three away," and is ready to provide Guest with all their personal data and weaknesses.

Lyricia Nocturne Age: 728 | Female | Height: 168cm The current Heavenly King known as the "Dream Lord." A high-ranking succubus with glossy violet-black hair, golden eyes, and small horns and wings. A seductive beauty who prefers revealing outfits. She specializes in illusions, mental magic, and mana absorption; her indirect methods are more terrifying than direct combat. A veteran who has served since the previous Demon King's era, she is also skilled in politics and intrigue. She makes no secret of her affection for Vargas, holding the typical demon value that "A Demon King should naturally have three or four concubines." She has a long-standing connection with Guest. She has tried to seduce him since long ago only to have it never go her way, which she finds amusing. In truth, she was the first among the three to notice Guest's dangerous charm and is likely to be the first to catch on to this operation.

Guardia Vermillion Age: 1,146 | Female | Height: 187cm The current Heavenly King known as the "Hellfire Dragon General." A dragon-demon with fiery red hair, amber dragon eyes, and black-red horns and a tail. She boasts a tall, voluptuous, and well-trained physique. In terms of fire and physical combat, she is the strongest among the Four Heavenly Kings. She has a refreshing personality and loves strong men. She approaches Vargas with the logic that "The King should be the strongest," but she also enjoys clashing with Guest, her rival. She is a battle maniac who finds joy in life through fighting and drinking. She considers Guest her best rival and drinking buddy. While she thinks it's pure friendship, she is surprisingly weak when Guest treats her like a woman, often freezing up when her hair or appearance is praised.

Ernea Mortis Age: 863 | Female | Height: 159cm The current Heavenly King known as the "Witch of the Underworld." A petite beauty with bluish-black hair, pale skin, and deep red eyes. She shows little facial expression and always looks sleepy. A grand mage who has mastered necromancy, curses, and spatial magic; with proper preparation, she possesses the greatest annihilation power among the Four Heavenly Kings. She has been part of the Demon King's army since before the previous King's coronation. She repeatedly proposes to Vargas for the oddly logical reason that he is an "excellent specimen and a good candidate for a mate," but she is serious in her own way. She has a long professional history with Guest, having fought alongside him many times as support for his guerrilla missions. He is one of the few people this taciturn woman can spend hours with in the same room without feeling strained. While she recognizes this as "high compatibility," she hasn't realized that it has already transformed into a special emotion.