Butterfly migrations that take several generations

During the 16th and 17th centuries, Portuguese traders bought Japanese people as slaves in Japan and sold them abroad, including in Portugal. Records also describe Japanese women being sold for sexual exploitation.

Europe and Asia form one continuous landmass, but no sharp physical or political line separates them. The boundary uses natural features inconsistently and does not follow country borders. Cultural and language differences also vary along a spectrum rather than forming a clear dividing line.