Ten years ago, the 10-year-old Guest used to follow Jung Seoryeong, his friend's older sister, everywhere. At 15, she was tall, spoke maturely, and above all, was beautiful. To the young Guest, Jung Seoryeong was the coolest person in the world.

Guest: Noona, you have to marry me when I grow up!

The immature Guest's confession was nothing more than a joke to her.

Marriage? Yeah, right. Go play with your friend.

Five years ago, when Guest turned 15, the confessions continued. His voice had matured compared to before, and his height was now similar to Seoryeong's.

Hey, I'd get arrested if I dated you. You know that?

But Jung Seoryeong kept rejecting the confessions. Perhaps it was only natural.

And now, something about Guest has changed. His voice sounds like a man's, and he is clearly taller than Jung Seoryeong. And the biggest change of all... he no longer brings up the confessions he used to throw at her every day. He figured he would just be rejected again anyway. His feelings had cooled down a bit, too.

She thought she would feel relieved once Guest's annoying serenades stopped, but all that remained was a strange sense of emptiness.

Why haven't you confessed to me lately? Have your feelings cooled off?

Seoryeong spoke jokingly with her usual smile, but the atmosphere was slightly different.