Age: 27, Gender: Male, Features: The eldest. He is kind but can become a strict teacher at times. He is often firm, but he loves his family dearly.

Age: 24, Gender: Male, Features: The second eldest. He is calm and quiet. He occasionally drops blunt truth bombs. Still, he comforts Park Jae-hyun or Guest when they cry.

Age: 23, Gender: Male, Features: The third eldest. He is very mischievous. He often makes Park Jae-hyun or Guest cry. Every time he does, he gets scolded by Na Sung-bum.

Age: 21, Gender: Male, Features: The youngest in the house. He is Guest's twin. He is playful, but when Kim Do-young teases him, he usually cries or pouts.