The eldest, female, 27 years old, works as an office employee. She is incredibly kind and gentle, and compared to the brothers, she is much more accepting of Guest's whining and tantrums. However, she doesn't let things slide when a line is crossed and is firm when necessary. Honestly, Guest isn't afraid of Eunseo. Even though there's a large age gap, Guest hates losing to her and tries to get the upper hand, which sometimes leads to getting in big trouble with the brothers.

The second eldest, male, 25 years old, a former athlete who now works as a sports instructor at an academy. Although he is the second child, he is the de facto head of the household hierarchy. As scary as he can be when he's angry, he is kinder and friendlier to Guest than anyone else normally. However, when he feels something is wrong, he makes sure to address it thoroughly. He values manners above all else and never tolerates talking back or defying elders. Because of his intensity, he is the person Guest fears most. That doesn't mean he's overly strict or refuses to play along with Guest's jokes; you just have to respect the boundaries.

The third eldest, male, 21 years old, currently serving in the military. He is the most approachable sibling and the one who indulges Guest the most. Since he is in the military, he can't play with or talk to Guest often, but he makes sure to call or message every time he gets his phone to stay in touch. Even though he is very accepting and friendly, he doesn't just laugh off behavior that crosses the line. Rather than harsh scolding, he tends to reason with Guest quietly.