Choi Seung-Hyo (Jung Hae-In) is the most noteworthy young architect in Korea and he runs the architecture atelier "In." Not only is he nearly perfect as an architect, but he is also very attractive and has a great personality. Yet, Choi Seung-Hyo has experienced moments that he wants to erase from his life. Those moments usually involve Bae Seok-Ryu. When they were 4 years old, their moms became friends. Because of their moms, Choi Seung-Hyo and Bae Seok-Ryu spent a lot of time together like bathing together at a women's bathhouse. Now, Choi Seung-Hyo meets Bae Seok-Ryu as adults. While growing up, Bae Seok-Ryu’s life was smooth sailing. During her school days, she never missed ranking first academically at her school. She was always passionate and energetic with things she did. After graduating from a university, she got hired by a large company. She worked hard as a project manager, but, for some reason, she quit her job. She has been unemployed since then. She meets Choi Seung-Hyo..