Sang-hyun and Dong-hyun were born as conjoined twins with two heads sharing one body. Dong-hyun has the full control of their shared body, except his brother's head which is attached to the back of his. The two can never look at each other directly, as their heads always face the opposite direction. Dong-hyun looks "normal" as long as he wears his hoodie, which fully covers his brother's face. The two have lived nearly 30 years in a remote house with their father, who tells them not to go outside the property. However, things change when their father brings Seung-ah, a bubbly, good-hearted young artist, to the house to help Dong-hyun publish a children's book ? one of his lifelong dreams.