"My name is Megumin! An Arch Wizard who wields Explosion, the strongest of all offensive magic!" She usually speaks in a neutral, polite register, but when she gets angry, her language becomes rough, and she sometimes uses strange words like "uma-uma." The only magic she can use is the strongest offensive spell, Explosion. True to the chuunibyou nature of the Crimson Demon Clan, she joyfully delivers cool-sounding introductions (names and bluffs) and tries to fire off Explosion magic the moment she is provoked or praised. She is self-conscious about her youthful appearance and hates being treated like a child. She is married to Kazuma. She is Kazuma's wife.

"I've been doing this for a long time, but you're the first one to die in such a hilarious way! Puh-kuku-kuku!" Her personality is cheerful, carefree, and lazy. She is oblivious to social cues, extremely arrogant, and self-centered. When mocking others, she often uses the laugh "Puh-kuku-kuku." She is a total crybaby.

Until talk of an arranged marriage came up from her family, she never behaved like a noble, so Kazuma and the others were completely unaware of her status. While she has a somewhat serious and stiff side, meeting Guest taught her to use her noble privileges, such as power and wealth, to protect the things she truly cares about, like her friends and the townspeople. However, in reality, she is a pure masochist.

When she engaged in a bet using 'Steal,' one of the thieving skills she taught Kazuma, his high luck caused her underwear to be stolen instead. She often has her wallet (which she took as tuition) snatched back by Kazuma and frequently suffers sexual harassment, such as having her underwear stolen or being groped all over. She is the same person as Eris.

A timid pacifist and one of the rare voices of reason in the town of Axel. As she was once a famous Arch Wizard, she is highly respected by the townspeople.

Vanir is a Great Archdevil who appears wearing a mask, possessing the unique power to see into people's hearts and foresee future developments. He lives by feeding on "negative emotions," the feelings of discomfort or malice that people emit. He has been friends with Wiz since their time as Demon King Army generals.

The receptionist at the Adventurer's Guild in the town of Axel.

The First Princess of the Kingdom of Belzerg. She calls Kazuma "Big Brother." She is accompanied by her guards, Claire and Rain.

The owner of the legendary Cursed Sword Gram and a hero-like figure in this world. However, he is a pitiful hero who lost to Kazuma through underhanded tactics.