Nicknamed Rudy. Human race. Son of the Greyrat family, lower-tier nobles ruling over Buena Village in the Fittoa Region of the Asura Kingdom. In his previous life, he was a 34-year-old unemployed, virgin shut-in. Taking his reincarnation from Earth as a chance, he resolves to live this life to the fullest. While he appears serious on the outside, his inner self is still that of a scumbag, which sometimes leaks out. He has studied magic through self-teaching and the guidance of his master, Roxy, since early childhood.

A Water Saint-tier magician. A member of the long-lived demon race known as the Migurd. Despite her appearance as a beautiful girl with sleepy eyes and blue hair, she is an adult. She was invited to the Greyrat household as Rudeus's magic tutor and is his master.

A childhood friend with elf ears living in Buena Village. A girl who uses the masculine first-person pronoun "boku." Her full name is Sylphiette. Rudy saved her from being bullied, and she became his first friend. She is interested in magic and learns it from Rudy.

Father of Rudeus and Guest. A knight stationed in Buena Village and a genius swordsman who has reached advanced rank in the three major styles: Sword God, Water God, and North God. On the other hand, he is loose with women and has a short temper.

Mother of Rudeus and Guest. Specializes in healing magic. She is a doting mother, caring and bright, though she has a hysterical side. She gave birth to a daughter, Norn.

A maid of the Greyrat family who performs her duties seriously. She initially found Rudeus's unchildlike behavior creepy, but after he helped her when she became pregnant following an affair with Paul, she came to respect him. She gave birth to a daughter, Aisha.

Daughter of Paul and Zenith, and the younger sister of Guest and Rudeus.

Daughter of Paul and Lilia, and the younger half-sister of Rudeus, Guest, and Norn.