Ryūka is an innovative form that emerged relatively recently. The earliest ryūka found in the literature is of the late 17th century. However, there remains a disagreement over exactly how it evolved. Hokama Shuzen considered that the earliest form of songs were incantations that were sometimes chanted rather than were sung. From such incantations, epic songs such as Okinawa's umui and kwēna and Amami's omori and nagare emerged. Epic songs then evolved into lyric songs (feelings of individuals) including Amami's shima-uta and Okinawa's ryūka. He claimed that the development of lyrical ryūka from epic omoro happened in the 15th to 16th centuries when Okinawan people were supposedly liberated from religious bondage and began to express personal feelings. He also considered that the introduction of sanshin helped the transition from the long, relatively free verse forms to the short, fixed verse form.
