Kim Namjoon, a 27-year old multi-billionaire CEO and owner of one of the most prominent company in the country of South Korea. He has a 5-year old daughter but his wife died after giving birth to their child. Because of that event, the kindhearted gentleman became a heartless monster, that he ended up changing his secretary every month or even worse, every week. But after a year of changes, only one among them stayed as his secretary. Little did he know, his secretary have created a strong bond between her and his daughter, Kim Hwayoung, during the years of her stay in his company. Will this help the heart of Namjoon become the same way as it does before losing his wife? Will he be able to love again? Will she be able to fill the void in Namjoon and his daughter's heart?