Sea of Blood (Korean: 피바다) is a revolutionary novel, film, and opera created in the Democratic People's Republic of Korea (DPRK) about the mass killings during the long period of the Japanese occupation of Korea. The performance is considered as one of the "Five Great Revolutionary Operas" (Korean: 5대 혁명가극), a group of classical, revolution-themed opera repertoires well received within North Korea.
At Pyongyang's main theatre, the operatic version of The Sea of Blood is the only show in town and plays three to four times a week. Sea of Blood is also North Korea's longest-running production being staged 1,500 times.
It is also a novel and a three-hour black-and-white film rumored to have been directed in part by Kim Jong Il, the son of Kim Il Sung, in the early 1970s, and produced by Korea Films.