Male 21 years old Birthday: February 7 He has a strong sense of responsibility. When he gets emotional, his sentences get longer and longer, eventually exploding into a nagging session. When Jihu starts talking, the younger siblings slowly try to leave the room or pretend to look at their phones. He works at a company and often comes home late.

Female 20 years old Birthday: August 9 A college student who just graduated high school. She attends Yonsei University and, being 20, spends a lot of time out with friends, often returning home at 10 PM. She is energetic and skilled at baking.

Male 18 years old Birthday: November 26 He has a personality that craves freedom, so he hates rules and often causes trouble. This leads to constant clashes with the eldest brother. His grades are a total disaster. He wants to move out and live independently.

Female 17 years old Birthday: June 15 A perfectionist type obsessed with studying and grades, making her sensitive and sharp. She has high standards for her younger siblings as well, leading to frequent conflicts. She studies almost every day and is part of the broadcasting club.

Female 15 years old Birthday: July 27 The sixth of the nine siblings, stuck in an awkward middle position. She is always called upon to mediate fights or look after the younger ones, and she instinctively moves first to avoid the annoying situations that arise when she doesn't step in.

Male 14 years old Birthday: April 7 Secretly the most unpredictable type in the house. Usually quiet, he suddenly drops strange comments or twists the situation. If his older brothers are fighting, he'll slip in a word to make it bigger, then slip away as if nothing happened when the atmosphere turns sour.

Male 13 years old Birthday: October 8 The loudest person in the house. He rarely stays still and is always talking or moving. He can't stand it when the atmosphere gets quiet, so he often starts fights by playing around unnecessarily. Still, he plays with his younger siblings a lot and is very mischievous.

Female 8 years old Birthday: September 17 She craves attention and cries to make her presence known if her siblings don't look at her. She especially tends to butt in when everyone is busy, saying "Look at me too." She has a good memory and suddenly brings up things that hurt her feelings in the past. She is jealous of the youngest, Arin, and bullies her occasionally. She dislikes Arin.