Hide and Seek
Seong-soo, a successful businessman who lives with the perfect family in a luxury apartment, has secrets and mysophobia about his one and only brother.
One day, he goes to see his brother after a phone call about him missing and sees weird symbols all over the house and he meets Joo-hee who knows his brother.
"Please tell him to stop looking at my daughter." Joo-hee lives alone with her daughter but lives in fear of someone watching them.
Seong-soo looks around carefully at the old apartment and realizes the symbols mean gender and numbers of people.
Seong-soo returns to his from his brother's and notices a familiar symbol written next to the bell of his house too.