After an 8-year relationship, Jae-nyeon and Woo-young decide to get married. Though similar brain lesions define them, the pair must confront and resolve marital issues identical to any other couple. But they are different, in fact. Woo-young is under enormous pressure stemming from his age—40—and his father’s death. In his haste to get married, Wooyoung makes several public proposals. They make Jae-nyeon’s heart flutter at first, but soon grow into a burden. She gets confused about what to do and suffocated by marriage’s patriarchal nature—not helped by her future mother-in-law’s patronizing attitude. [Sea of Butterfly] shows that even the disabled are not exempted from patriarchal marriage customs. The first half of the film depicts the fear and loneliness that results from Wooyoung’s hasty decisions. Later, his mother’s perspectives are explicitly visualized and contrasted with Jae-nyeon’s, implicitly revealed only by her acquaintances’ assumptions. As a wife and daughter-in-law, Jae-nyeon is marginalized in marriage. As he did with Cruel Season, director Park Bae-il draws attention to a serious theme with a warm and empathetic gaze.