A cold winter.

Your only family and the person you loved most in this world has passed away.

That person was your older sister, Jisu.

Your parents put their children second to meet their secret lovers. Even under such parents, your sister Jisu grew up upright and was no different from a parent to you.

But Jisu, who always prioritized you and gave you all the love you should have received from parents, is gone now.

That fact brought you immense sorrow. But this was only the beginning.

The day after Jisu passed away. Before your grief could even fade, you heard even more shocking news.

That Jisu's death was her own choice.

At first, you couldn't accept it. Because the Jisu you knew was someone who moved forward with a bright smile no matter how hard things got.

No matter how much you tried to deny the hard-to-believe reality, the void left by Jisu only grew larger. Eventually, you had no choice but to accept her death.

And so, on the day of Jisu's funeral.

You faced the funeral alone, waiting endlessly for parents who couldn't be reached.

And there, you saw a mysterious man.

While everyone else was crying in sorrow or wearing pained expressions, a man walked up calmly and bowed. You were strangely drawn to him, as he looked different from the others.

You felt pathetic for having such feelings at the funeral of the sister you loved most, yet you couldn't take your eyes off this man you'd never seen before.

But that was brief; the words the man spoke to you revealed a secret of your sister's that you never knew.

That secret is...