Park Kairen (Son Ye-jin), a furniture designer with a simple and kind nature, is an incurable confused woman. Her boyfriend Han Changyeol (Kim Ki-seok) is about to get married to her good friend Kim In-hee (Wang Ji-hye), but she is completely unaware of it and mistakenly thinks that her boyfriend is going to propose to her. Kairen, who is slow to realize it, is in great pain because of the double betrayal of friendship and love. Under various misunderstandings, she met the architect Jeon Jin-ho (Lee Min-ho). Not only do the two of them dislike each other, but Jin-ho is also mistaken by Kairen as a homosexual. Jin-ho's previous design model was messed up by Kairen, causing his company to face a crisis of bankruptcy. In order to save the decline, he made a desperate bid for the art museum project. In order to make the most perfect design, he transformed into a tenant and moved into the world-famous Nagoya Shangkojae, but the owner of Shangkojae turned out to be Park Kairen. In order to save his career, Jin-ho pretended to be a homosexual and began to live with Kairen.