Babyls Demon School (悪魔学校バビルス Devil School Babyls) is a prestigious school in the demon world run by the principal, Lord Sullivan.
The renowned academy has been teaching students of both lower and higher status of demon families, facilitating their predestination by increasing, or to a extent, decreasing their demon ranks as they stay in the school.
Babyls's school is located at the top of the huge cliff with its surroundings greatly resembles uncanny mountains. There are a lot of towers inside the academy, as well as several spiky-like buildings present all over the place. There are also fences surrounding it, but the exterior walls of the school is high enough to be regarded as a partition from outside. Babyls can be reached either by aerial (by demons flying) or simply by walking and entering through the a large gate in the center, of which is most probably the only entrance to the school.
There are a total number of 666 students currently enrolled in the school, spread out through 6 grades. Iruma's batch (the first year students at the start of the series) consist of 163 students that was then divided into class groups A, B, C, D, and the Abnormal Class.
First Year Tower
Alma Mater Anthem
Humans only exist to be our food
Suck them dry, soul, blood, flesh, and all
Tremble at the sound of black wings as we take flight
For we are demons
As this song pours forth from our red lips
Scream for us, for we are demons
Our castle is the greatest evil
Its name is Babyls, a solitary place for study
Sacrificing our souls, blood and meat without leaving anything behind
We shall aim for the demon's top
Ningen marumaru warera no kuimono
Tamashii, chi to niku nokosazu susure
Kuroki tsubasa no habataku oto ni
Anonoke monodomo warera wa akuma
Akaki kuchi kara koboreru uta ni
Sakebe yo, monodomo warera wa akuma
Aku wo kiwameshi warera no kyojou
Sono na wa babirusu kokou no manabiya
Tamashii, chi to niku nokosazu sasage
Akuma no itadaki mezaseyo warera
For more information, see Demon Ranking System.
Babyls runs off the same ranking system used by Demons throughout the entire demon realm. It is during school that demons can gain their first rank, and continue ranking up, which corresponds to a rise in social status.
Demons of the top rank, Yodh, are candidates for the title of "Demon Lord".
All students are required to study academically, although there are some options of different subjects that they can choose in associating to their likeness. Some are done only at the start of their year and optional after or are required for all students to partake of. Few of the subjects are gender-exclusives as well, but overall they are mostly to be done recurrently throughout the year. These are prerequisites subjects and elective subjects respectively.
List of Subjects
- Interacting with familiars
- Classroom Lectures
- Seduction (Girls only)
The purpose of Batras (or Battlers) is to gather students of common skills and interests to interact with each other to help improve either magic, knowledge, physical prowess as well as train leadership skills. Depending on how good they perform, they may rise up in ranks. According to Asmodeus, Batras are groups that focus on raising ranks. About 60% of the total population of Babyls' students are in a batra as it is one of the best ways of forging necessary relationships or connections with upperclassmen. There is a Batra Tower in the school specifically for such activities. 
Lists of Batras
- New Magic Batra (Magecraft Development Batra)
- Magical Tools Research Batra (Magical Apparatus Batra)
- Diabotany Batra (Diabolical Botany Batra)
- Aviation Batra
- Combat Batra
- Magic Creatures Batra
- Pharmaceutical Studies Batra
- Succubus Batra
- Game Batra
- Discipline Batra
- Library Batra
- Broadcast Batra
- Demon King Document Studies Batra
- Black Magic Batra
- Rock-Paper-Scissors Batra
- Execution Cannonball Batra
- Ladies' Studies Batra (Non-Official)
- Our Batra (in the spinoff)
Within Babyls there exists a class-run student council. Even though the Student Council is being considered as a Division, this council mainly oversees a variety of duties, including organization of student events, student discipline and student clubs. The current Student Council President is Azazel Ameri, known for her strict and often violent discipline. School and demon culture can make discipline rather odd; on occasion, students can be lectured and disciplined for causing trouble halfheartedly and punished more severely than if they'd caused more damage. For example, a student has been seen scolded for destroying school windows, but not for bothering to break down the walls.
- Mairimashita! Iruma-Kun Anime Episode 6
- Mairimashita! Iruma-Kun Anime Episode 2
- Mairimashita! Iruma-Kun Anime Episode 11
- Mairimashita! Iruma-Kun Anime Episode 12