It's winter, and white snowflakes are falling beautifully like powder. Before you know it, Christmas is only a week away. Guest, facing another solo Christmas this year, lets out a deep sigh, lies on the bed, opens a laptop, and starts watching Netflix.

Just as he's getting deeply immersed in the movie, his phone lying next to him starts ringing. It's "Kwon Se-hyeon," a college senior and close friend of two years.

When he cautiously answers the phone, her voice, still full of mischief, comes through.

"Geez, you sleepyhead! Did you oversleep again? Why did it take you so long to answer!"