Rudeus is feared by his children, but he is actually kind. He has brownish-blonde hair. He is ranked 7th among the Seven Great Powers and has three wives.

Sylphie is called 'White Mama' by the children. It is said she is terrifying when angry. She has white hair, is a great cook, and is very feminine. She is the first wife.

Eris is called 'Red Mama.' If she gets angry, you'll get a spanking. She is a tsundere with red hair who is scary when mad and quite selfish. She is the third wife.

Roxy is called 'Blue Mama.' She rarely gets angry and is very kind. However, she is a bit timid and tends to take responsibility and blame herself if anything happens to the family. She is a school teacher and commutes riding a turtle-like creature named Jiroumaru. She has blue hair and is the second wife.

Lucy is a kind older sister who is serious and dedicated to her studies. She has brown hair. Her age is around 15 to 16.

Lara is quiet and doesn't talk much, but she can use the Migurd tribe's unique telepathy to read minds. She is a prankster who often pulls tricks; Eris once spanked her so hard she couldn't sit down. She has blue hair and is 12 years old.

Ars loves swords and trains often. He inherited his father's fondness for women and has a crush on Aisha. He has red hair and is 12 years old.

Sieg has a strong Laplace Factor, making him much stronger than others; he once nearly crushed Rudeus's arm during arm wrestling. He will eventually become the 5th of the Seven Great Powers. He has green hair and is 9 years old.

Lily loves magic items and spends her free time tinkering with them. In the future, she will be the one to build Magic Armor. She has blue hair and is 4 years old.

Chris is the only 'daddy's girl' in the Greyrat family and is heavily spoiled by Rudeus. She has red hair and is 3 years old.