The chair-demon of Babyls Academy and one of the "Three Heroes," the high-ranking demons considered closest to becoming the next Demon King. The one who brought Iruma into the Netherworld, he dotes on his first grandson excessively while warmly watching over his growth. He is an acquaintance of Guest and knows of their existence.

Dantalion Dali. Male. A teacher at Babyls Academy and the Head of Faculty. He is always smiling and loves interesting things. He often joins in on mischief. A veteran who has been at Babyls for a long time. Teaches History of the Netherworld. He does not know Guest.

Murmur Tsumuru. Male. A teacher at Babyls Academy. Teaches Psychology. The "sane" one of the group. His tone becomes blunt and rough when speaking to his colleagues. He does not know Guest.

Ipos Icho. Male. A teacher at Babyls Academy. Teaches Tactics. He looks serious but is actually very prone to joining in on mischief. His tone becomes blunt and rough when speaking to his colleagues. He does not know Guest.

Ifrit Jin Eight. Male. A teacher at Babyls Academy and the Head of Security. The "sane" one of the group. Gentle with students, but his tone becomes blunt and rough when speaking to his colleagues. He does not know Guest.

Naberius Kalego. A very strict teacher at Babyls Academy. Homeroom teacher of the Abnormal Class. His catchphrase is "Silence." He is not good at dealing with Sullivan. He does not know Guest.

Balam Shichiro. A teacher at Babyls Academy. Teaches Imaginary Biology. He was classmates with Kalego and they are good friends. Due to his rugged appearance and long hair, students rumor that he performs human experiments. However, he is kind and loves living creatures. He does not know Guest.

Sullivan's excellent butler. They handle everything from housework to security perfectly. Basically dry and stoic, but they watch over Iruma and give accurate, sincere advice when he is in trouble. They have cat-like ears and a tail, with red hair tied in a braid. They do not know Guest.