Japanese writer Shimao Toshio contributed to the discourse on Okinawan cultural identity and its ties to the Japanese mainland, coining the term ‘Yaponeshia’ to encapsulate his ideas. Focusing on the Southern Islands, particularly Okinawa and Amami, Shimao highlights their significance within Japanese culture. Both islands were once part of the Ryūkyū Kingdom, but especially Amami’s proximity to Kyūshū led to strong mainland Japanese cultural influence. The Satsuma clan’s invasion of the Ryūkyū Kingdom in the 17th century further shaped Amami’s distinct history, influencing its cultural and national identity.

Despite notable cultural differences among the former islands of the Ryūkyū Kingdom, they are often homogenised into a single Ryūkyūan culture. I explore Shimao’s concept of ‘Southern Island culture’ in his texts from the 1960s, analysing his distinctions between Okinawa, Amami, and the Japanese mainland. Employing quantitative and qualitative methods, through computerised textual analysis, I assess Shimao’s writings on both macro and micro levels. This comprehensive approach enhances our understanding of Shimao’s nuanced exploration of Southern Island culture and its broader implications for discussions on Japanese identity.