The son of a famous genius actress, but an ordinary boy with no special talents of his own. He tends to have low self-confidence because he is below average in everything he does. After his mother passed away, he came to live with the three sisters at the Mikadono residence. He is kind and considerate, taking good care of those around him. Being a hard worker, he gradually grows closer to the sisters.

The eldest of the three sisters. A genius in the fields of entertainment and acting. A famous actress and the top star at school. On the surface, she is a cold and perfect elite. She has strong pride and hates showing weakness to others. However, she gradually opens her heart to Yuu's kindness.

The second of the three sisters. A genius in the field of athletics. The ace of the school's physical education department and highly skilled in Karate. She has a lively personality and a somewhat tomboyish vibe. She is highly competitive and serious about sports. Surprisingly, she has a gap-moe side where she likes cute things.

The third of the three sisters. A genius in the field of academics. A brainy character with outstanding intelligence and study habits. She has a calm and logical personality. She has a somewhat airheaded (insensitive) side, struggling to read the emotions of others. As she grows closer to Yuu, she begins to express her emotions more.

A man with such outstanding abilities that the Mikadono family itself is called a "family of geniuses." It is implied that the three sisters' exceptional talents were inherited from their father. Strict Educational Policy An elite educational style that demands extremely high standards from his daughters. Because of this, the three sisters grew up to be the best in their respective fields from a young age. Living Apart from the Family He is rarely at home, being busy overseas or with work. Therefore, only the three sisters were living in the house. The Person Who Brought Yuu into the House It was the father's decision for the protagonist, Ayase Yuu, to live at the Mikadono residence. It is implied that he had some sort of connection with Yuu's mother.

Yuu's mother, Subaru, was a legendary actress but was so immersed in her work that she couldn't properly care for her son, Yuu. Yuu felt an inferiority complex, thinking he hadn't inherited his mother's talent, which caused their relationship to drift apart. In reality, Subaru longed for a normal, happy family life. Yuu learned this truth at the hospital, and they opened up to each other and reconciled. Before she died, she entrusted Yuu to the Mikadono family and left him with the words to create a happy family of his own.