After realizing her BFF is now dating another BFF she had a crush on, Hee-won is heartbroken. Hoping to lift her spirits, she engages in a one-night stand with a handsome stranger. To her surprise, their encounter results in a pregnancy. Faced with an uncertain future, Doo-joon enters the picture and proposes marriage. However, the two have little familiarity with one another, aside from their physical intimacy. What should this soon-to-be mother do?