This story, based on historical events, is compelling and The Samurai renders the worlds of 17th century Japan and Europe, as seen through both native and foreign eyes, quite vividly. A Catholic himself, however, Endo makes it more an exploration of the nature of religious faith than of the world.
The Samurai switches backwards and forwards between two perspectives. Half of it is told in the first person, as the journal of Franciscan missionary Velasco, who accompanies the envoys; he dreams of being appointed bishop of Japan and his worst enemies are not the Japanese lords attacking Christianity but the Jesuits who take a different approach to missionary activity and send scurrilous reports about him back to Europe.
The other half, in the third person, follows one of the Japanese envoys, Hasekura, who is mostly referred to as simply "the samurai". A low-ranking samurai whose domain consists of poor marshlands, his family hopes for restoration of wealthier lands lost when they took the wrong side in a war, though he himself is quietly accepting.
Some of the other envoys are also finely drawn, but these two are the central masterpieces and their authenticity prevents Endo's account lapsing too far into the confessional. Velasco's greatest sin is his pride, while Hasekura, whose loyalty and trust in his superiors epitomises contrasting virtues, converts only as a matter of convenience. In their different ways they both wrestle with their doubts and they both find martyrdom.