Taiyou no Mokushiroku: A Spirit of the Sun is set 15 years after a devastating series of natural disasters split Japan into two halves, with China governing the North and the United States governing the South. Many Japanese refugees, including main character Genichiro Ryu, who was adopted by a Taiwanese couple, now live in Taiwan. Tensions arise between the Taiwanese and Japanese populations as they compete for jobs and struggle with living conditions. Ryu becomes embroiled in this conflict, seeking a way for the two groups to peacefully coexist.