;: Kucabara is the protagonist of
Defense Devil and the third son of the great demon king. After being stripped of his powers, Kucabara becomes a lawyer in order to make a living. His duty as hell's lawyer is to prove an unknown soul's innocence to prevent them from going to hell. Before he was stripped of his powers Kucabara was said to have the strongest dark matter in the demon world. Also Kucabara has openly expressed his feelings for Idamaria by proclaiming his love to her. ;: Bichula is the formerly strongest warrior of the famous dragon family, which was massacred by the kingdom of the underworld. He was stripped of his powers and banished from the demon world along with Kucabara. ;: Elimona is a fallen angel from heaven who runs a store in Event Horizon, a land between the real and demon worlds. She frequently cosplays and tries to seduce Bchuler and Kucabara, much to their chagrin. However, she is often turned to for help or advice by the protagonists. In chapter 85 she revealed to Idamaria that she is an angel and wanted to destroy the demon world by releasing the goddess
Lilith. ;: Idamaria is a
nun who specializes in demon
exorcism and is romantically interested in Kucabara. It is later revealed that Idamaria is able to produce dark matter from her body. In chapter 72 it is said that her name before entering the church was Catherine. ;: Selma is a priest in charge of the institution where Idamaria lives. He is the one who trained Idamaria and Kucabara to cooperate with each other in order for them to open a portal to the demon world. A powerful exorcist, he is acquainted with Elimona and obtains information about the demon world through her. His name before dying was Kanto. ;: A proud, apathetic, and analytic shinigami-ranked demon whose attacks are based on
mathematical formulas. He hates underlying schemes and would even revolt against Legato for his ethics. During his stay in the orphanage, he grew fond of a young girl named Jupiter and seeks to free her parents from hell. ;: Legato is the primary antagonist of the series and the fourth son of the great demon king, Kucabara's younger brother. After plotting Kucabara's banishment, he received all of Kucabara's power. ;: The newest member of Kucabara and the others. She was betrayed so many times that she despised relationships and settled out to destroy them. Her original plan was to ruin Kucabara's and Bchuler's relationship and kill them, but she ends up joining their cause. She wields a rifle. ;: A little girl taken in by the institution run by Father Seruma when her parents were killed in an accident. She was abducted by the many shinigami who were working for Legato in order to lure Kucabara into going to the demon world. She becomes attached to Sugal after he saves her. ==Publication==