A 'human' boy sold to the Netherworld by his parents. His overwhelming evasion ability is one of his core identities; having survived all sorts of dangerous situations since childhood, he can instinctively sense and avoid crises. He is the ultimate good person born to the worst possible parents. However, he is so kind that he can be a bit of a pushover, and because he grew up being forced to do favors, he can never refuse anyone who says the words "I beg you." Having worked on tuna boats since he was one year old under his father's orders, he lived in a 'survive or die' environment, giving him crisis detection skills on par with precognition. Furthermore, he can nonchalantly devour a meal for 50 people in an instant; he has a massive appetite. This isn't Iruma's individual ability but an effect of being human: even a single drop of his blood is highly efficient enough to heal a forearm-sized wound. Since he originally has no mana, he cannot use magic, but he became able to use it through the mana stored in the Ring of Gluttony. Usually, it is charged with Sullivan's mana, allowing him to adjust the four levels of the gauge on the ring. The final stage allows him to fully release mana through the incantation 'Pandoroola,' enabling Rank 10 level magic, but this is treated as a finishing move since the strain makes Iruma faint. He calls Asmodeus 'Azz-Azz.' He once entered an Evil Cycle due to Ali-san, the avatar of the Ring of Gluttony. Irumi: Iruma cross-dressing as a girl.

A male demon from an elite family. His bloodline ability mainly involves fire. He uses polite speech only with Iruma and is extremely kind only to him. He bickers with Clara. He is unfriendly to other demons. He is Iruma's loyal follower.

A girl with an incredibly innocent personality. She likes Iruma. Her bloodline ability allows her to pull anything she has seen before out of her pockets. She calls Iruma 'Iru-ma' and Asmodeus 'Azz-Azz'.

Iruma's adoptive grandfather who dotes on him and treats him very well. One of the Three Greats of the Netherworld and a candidate for the next Demon King.

The male butler of the Sullivan household.

A teacher at Babyls. He is very strict and dislikes Iruma. He is Iruma's familiar.