
Iruma Suzuki, the most prominent example of a Human who mostly appears throughout the series.
Humans (
Overview[]
Humans are people who live fairly mundane lives. Compared to demons, their strength and power are far lower than the latter as they cannot use Magic and are physically much frailer. The most well-known human is the titular Iruma Suzuki, a 14-year-old boy sold by his parents to Lord Sullivan, who adopted Iruma as his grandson.
Connection to Demons[]
Although both the Human World and the Netherworld are mostly separated, with each one largely unaware of the other, several stories narrate humans forging contracts with demons for power in the past. However, at present, no such practice is done; many demons believe that humans are a myth and do not exist, which is expected as neither side has any real interaction.

a human hot pot
This puts the ancient stories into question as to whether there was any truth to them or not. Ironically, the Babyls Demon School has its signature hymn declaring that humans exist purely to be the food of the demons, although, in actual practice, many demons are puzzled as to why, given they have never met any human before. However, when Naberius Kalego became Iruma's familiar following a summoning ritual, largely due to Iruma's nature, it gives credence to these very stories. According to Balam Shichiro, humans are a delicacy for demons because they are full of desires, but he also mentioned that they are a protected species. This seems contradictory, with Babyls' hymn being sung for every school occasion. It could suggest that one of the reasons why the masses are led to believe that humans are imaginary creatures is to protect the latter. It is also further suggested, as Azazel Henri said Demon Border Control usually sends humans back to the human world. If found, it hints that Iruma isn't the first human to end up there.
Due to Sullivan warning Iruma to not let his identity as a human being known, going as far as imbuing him with a scent that masks Iruma's human nature, it is thus hinted that demons can, indeed, if given a chance to eat humans in their proximity. However, it's unclear if this is because of an antagonistic relationship between the two races that took place in the past or if it's just a demon theory.
As seen with Iruma and his circle of friends, it is evident that both races can indeed coexist peacefully. However, it is also important to consider that the biggest reason for this is the fact that Iruma's true human nature is not public.
Human Blood[]
Human blood has magical properties in the Netherworld. It can heal demon beasts and make plants grow tremendously faster and bigger. When used for the blood pact of a summoning ritual, instead of invoking a magical beast matching the personality of the demon doing the invocation, it invokes the closest demon nearby or the demon with his mark on the familiar-summoning parchment.