CEO Seung-tae is in an affair with his sister-in-law So-young who works for him. One day, a rookie named Young-chul finds out about them and threatenens So-young that he'll tell the CEO's wife about them and spends anight with her. He continues to threaten and bully her. So-young is scared that her affair with her brother-in-law will cause trouble with her half-sister Hye-sun...