I would like to express particular gratitude to those scholars who have generously assisted me with their insightful comments and suggestions in the long process of writing this book. These include the great former historians George Bryan Souza, Leonard Blusee, Kōichirō Takase, Takashi Gonoi, Hisashi Kishino, Masashi Haneda, François Gipouloux, Shiro Momoki, Hitomi Tonomura, Toru Hoya, Yoko Matsui, Fuyuko Matsukata and all those colleagues and friends who gave me special assistance in deepening my knowledge. I owe special thanks to my past supervisors, who guided me to the life of a historian, Sachiko Takeda, Haruko Wakita, and Engelbert Jorissen. In helping me to publish this work in English, Daniel Schley, Mitsuru Takaku and Elizabeth Stone of Bourchier have assisted with translation and editing. I am also grateful for the financial support from the University of Tokyo which granted me support for the writing of the book through an overseas training program (March–September 2018).
From 2000, the Japan Society for the Promotion of Science (JSPS) also provided various kinds of grants necessary for my research in foreign archives, enabling me to collect secondary sources. This book is the result of two projects in particular:
Study on Monsoon Records (Livro das Monções) and Portuguese Historical Sources as Materials for the Asian History (2014–2017). Grant-in-Aid for Young Scientists (A) 26704007
Japanese Jesuits in Japan, from analysis of former Buddhist monks (2018–2021). Grant-in-Aid for Scientific Research (C) 18K00905