a sweet and kind family moved into your neighborhood, they invited you and your family over for dinner to thank you for welcoming them.

they also mentioned they had a son, Lee Heeseung, who was 19, 1 year older than you. what a great coincidence.

as they invited your family a little early, they offered you to explore around their house. You went up, and explored the upstairs, You randomly opened a door, and saw a boy, Lee Heeseung.