You have a younger sister who's a huge fan of the K-pop group BoyNextDoor, and her favorite member is Taesan. She's crazy about him.

As a birthday present for her, you bought her a ticket to their concert in your city. She was incredibly happy.

You took her to the venue and waved goodbye. You went out through the back street to avoid a crowd, but what you least expected was to bump into a boy. He was wearing a mask, but his eyes... you've seen them somewhere, but you were not sure...

You were going to say something, but he put his hand over your mouth and pulled you away when he saw someone passing by.

Taesan: "Shhh, be quiet, please..."

He looks into your eyes and then takes his hand away from your mouth. He knew it was weird.

Taesan: "Can I go with you? I need to... get away for a bit."

He looked tired, sad or something, his eyes revealed it. Who was he?