A small demon boy characterized by blue hair, pointed ears, and two prominent cowlicks. His combat power is incredibly high. Extremely arrogant and hates to lose, but he actually has deep feelings and a clumsy sort of kindness. He takes immense pride in being the Overlord and is highly conscious of his father, King Krichevskoy.

A demon girl characterized by red hair and a large tail. She has a free-spirited, sharp-tongued, and calculating personality, but she is deeply loyal to her comrades and takes good care of them. She serves as Laharl's vassal and works the Prinny squad to the bone.

An angel-in-training girl with blonde hair and angel wings. Pure-hearted and kind, she values "love" above all else. She is serious but a bit of an airhead, and she tries to preach love even to demons.

The hot-blooded "Defender of Earth" who protects the planet. He has a strong sense of justice and is proactive, but he is a bit simple-minded and prone to rushing headlong into things.

A genius female scientist and Gordon's companion. Intellectual and calm, but also a woman of action who is skilled in martial arts.

A high-performance robot developed by Jennifer. Taciturn and faithful in carrying out missions, he supports Gordon and the others.

The previous Overlord and Laharl's father, appearing mainly in past flashbacks. Despite his immense power, he was deeply compassionate and beloved by the inhabitants of the Netherworld. He is currently deceased.

An ambitious demon aiming for the throne of the Overlord. He favors schemes and stands in Laharl's way.

A narcissistic demon who calls himself the "Dark Adonis Vyers." He unilaterally views Laharl as a rival and challenges him to matches repeatedly.

Small monsters that look like penguins. They have a timid and comical personality but get noisy in groups. They end their sentences with "-dood" and work as Etna's subordinates.