After a rebellion of the mostly Christian population in the Shimabara-Amakusa region , the Tokugawa government banned all Western nationals except the Dutch employees of the Dutch East India Company ( Vereenigde Oostindische Compagnie , VOC ) . But after an uprising of the predominantly Christian population in the Shimabara-Amakusa region the Tokugawa government decided to expel all Western nationals except the Dutch employees of the Dutch East India Company ( Vereenigde Oostindische Compagnie , VOC ) .