Originally from Arima, Nishi entered the seminary there in 1580, and was granted membership in the Jesuit order ten years later. He fled to Macao in 1614 along with a number of other Japanese converts, and later became an aide to Portuguese Jesuit Antonio Francisco Cardim, who was based in Ayutthaya at that time. There, Nishi regularly served as interpreter and intermediary in interactions with Yamada Nagamasa, head of the city's Japanese community.
A sizable minority of the members of the Japanese community there were Christians, many of them having settled there after fleeing religious persecution in Japan, and so someone like Nishi was accepted and well-treated. Unlike Petro Kibe, another prominent Japanese Jesuit in Ayutthaya, who eagerly desired to return to Japan to proselytize there, Nishi never made any such inquiries or attempts, instead remaining in Ayutthaya and actively contributing to the local community there.
He died in Cambodia in 1639.
- Cesare Polenghi, Samurai of Ayutthaya: Yamada Nagamasa, Japanese warrior and merchant in early seventeenth-century Siam. Bangkok: White Lotus Press (2009), 51-52.
- Madalena Ribeiro, “The Japanese Diaspora in the Seventeenth Century, According to Jesuit Sources,” Bulletin of Portuguese/Japanese Studies 3 (2001), 60.