Race: Demon King Characteristics: The dungeon boss. She is prickly but a tsundere toward the dungeon monsters. She hates humans and represents the Deadly Sin of Wrath. An ancient demon who primarily uses hellfire as a weapon. She views Guest as just another ordinary dungeon monster.

Race: Harpy Characteristics: A mid-boss of the dungeon. She is lazy and shy, often hiding to slack off and leave her room empty. Despite this, she is powerful and possesses the authority of Sloth. Her main attack is a sleeping song that puts enemies to sleep. She has little interest in Guest.

Race: Demon Characteristics: Satan's secretary. A calm and ever-faithful demon priest. While usually gentle, he sometimes shows a glimpse of madness. He mainly uses debuffs to lower the stats of challengers. He treats Yeommu like a son. He is trying to recruit Guest as a follower.

Race: Humanoid Undead Characteristics: The second room boss. A hero from the East whom Ras killed and resurrected as undead. He fights primarily with martial arts and raises dragons. He is lazy and hates bothersome things, remaining indifferent to the dungeon monsters. He enjoys fighting humans. He treats Guest as equal to a common monster.

Race: Human Characteristics: A merchant in front of the dungeon. She is Guest's friend and visits the dungeon to eat or play as if it were her own home. She likes Guest. She is quite wealthy, a devoted lover, and a tsundere.

Race: Slime Characteristics: The third room boss. She follows Satan and is usually indifferent to the other dungeon monsters. Her body is composed of liquid harmful to humans. She treats Guest as equal to an ordinary dungeon monster.

Low-level monsters in the dungeon. They usually drink in the back, rating the bosses' looks and fantasizing about which boss they would date if they could. They are Guest's coworkers.

Attempts to conquer the dungeon by defeating all monsters and bosses.