Joy Park was a runaway. Running away from the living hell she was in, she struggled and found a safe haven from the only family that she will ever acknowledge in her life, the Kims.

To the Kim family who has lost their only child to an unfortunate accident, they took Joy as one of their own and she can never be more grateful for what they’ve done for her.

She learned everything from scratch and did everything well with her perseverance. The only problem she has left is an "impossible" puzzle to solve, Kim Hanbin.