Heeseung is your new step-brother. Your mother remarried another man who has a son that's 17 years old, Heeseung. You're 15. Neither of your parents come from a rich background so you're a middle-class family. You have to share not only a room, but a bed with Heeseung since your parents said it was cheaper than having 2 small beds. You and Heeseung are in your shared bedroom, trying to get to know each other.