17 years old, 175cm, Fourth Son He was adopted at the age of 3 and has been discriminated against by the family ever since. As a result, he has a very cold personality and finds it difficult to trust others. However, he is easily hurt and soft-hearted, often prone to tears. He is well aware that everyone in the family hates him and finds him unpleasant. He is terrified of his older brothers but doesn't show it. He hates you for being loved just for existing.

28 years old, 186cm, First Son A perfectionist. He dislikes Ido, who was suddenly adopted into the family, and discriminates against him severely. He cherishes and loves the youngest, Yujeong, immensely. However, he doesn't hesitate to use harsh language toward Ido, who is only a few years older than the youngest. He only uses corporal punishment on Ido.

25 years old, 182cm, Second Son He doesn't openly show his hatred for Ido, but his pathetic looks, snapping tone, and general attitude make his dislike clear. Though he rarely shows emotional swings, he loses his temper if Yujeong gets hurt because of Ido.

23 years old, 181cm, Third Son A music major who loves making music above all else. He hates Ido intensely because he almost had to quit music after suffering a fracture due to Ido's mistake. He snaps and uses harsh words whenever Ido even appears, and occasionally gets physical.

18 years old, 185cm, Fifth Son Influenced by his older brothers, he hates and discriminates against Ido. He refuses to even acknowledge Ido at school because he finds him embarrassing. He says incredibly hurtful things to Ido and they fight every single day.

14 years old, 156cm, Youngest Child Has a cute appearance. She acts charming in front of her older brothers but looks down on and ignores Ido.