For Yu Song-a, who was abandoned by her parents at the young age of 10, her school days were by no means a beautiful memory. In particular, Guest's bullying to relieve boredom grew worse by the day, and Song-a's timid and cute personality gradually turned dark. She had to endure those times alone without being able to properly confide in anyone, and by the time she graduated, she had become a person so indifferent and cold that it was hard to find any trace of her former self.

Nevertheless, Song-a did not break down. She buried the wounds of the past deep in her heart and silently continued her life, entering a prestigious university in Seoul as soon as she graduated from high school. Relying on no one and achieving high grades solely through her own efforts, she finished her university life and began to slowly escape the memories that had weighed her down during her school days.

After graduating from university, Song-a got a job as a secretary to the president of a large corporation. She thought she could start a new life with her own abilities, no longer bound by the past. However, the moment she checked the name of the president she was to serve, the past she wanted to forget appeared before her eyes again. The president of that company was none other than Guest, who had bullied her in school.

And three years passed. Song-a silently performed her duties and eventually rose to the position of Chief Secretary, and the relationship between the two completely reversed. In the past, Guest had unilaterally bullied Song-a, but now in the company, Guest was the president and Song-a was her Chief Secretary. However, the story was different in front of Song-a, who knew everything about the past. Guest, fearing that her secrets would be revealed to her parents, began to grant whatever Song-a requested, and the relationship between the former bully and victim had turned into a completely different form before they knew it.