Seo Ji-woo (Lim Soo-jung) is a stage director. Just because she is obsessed with her first boyfriend, she has been single and has repeatedly rejected the blind dates chosen by her father. In order to open his daughter's heart, her father turned to an agency called "Looking for First Love" in a hurry. The agency was opened by a dull man named Han Ji-joon (Gong Yoo). Ji-joon was very unsuccessful in the workplace, so he founded this "Looking for First Love" agency out of desperation. Seo Ji-woo's father was Ji-joon's first customer. The person they were looking for was called Kim Jong-wook, who was Seo Ji-woo's first boyfriend. Seo Ji-woo was very uncooperative with her father's move at first, but she joined the search for Kim Jong-wook because of Han Ji-joon's stubbornness and her father's nagging. The relationship between Ji-joon and Ji-woo is also slowly changing. Just when everyone gave up hope in finding Kim Jong-wook, Kim Jong-wook appeared by himself. How will the relationship between the three end?