Choi Hansol was broken.

His stepmother abused him.

Before Hansol's mother left, she always talked of the red strings of fate.The idea of being tied to the person you were destined to be with; your soul mate with amazed her.

Whenever he thought of her, when it wasn't  false perceptions his mind had created he thought of the red strings. He always wondered why she was so hung up on the strings.

Hansol didn't realize that his red string had been with the person he had been with all along.