In 1936, NHK started radio program to compete with "ryūkōka", which was under the influence of "Ero Guro Nansensu", but it soon began to air war songs around July 1937. The program was renamed to in 1941 and then in 1942. The songs during the war were called . During the war, many musicians were forced to write war songs. Yuji Koseki composed many war songs and was later criticised as a war collaborator, though he seemed to be touched with remorse. Koseki composed released in 1937. Although the song was a B-side song, it sold 600,000 copies. The 1937 song sold 1,000,000 copies. However, Japanese jazz musicians such as Ryoichi Hattori seemed to be vigorless to compose war songs. His son Katsuhisa Hattori claimed that he was not an antinationalist and he technically were hardly not able to compose war songs even if they wanted to make those because Japanese war songs were musically "enka".