I conducted the field researches on “Davao Frontier History—Focusing on the Relations between Japanese Manila hemp cultivators and the Bagobo tribal people on 20 January–1 March and 25 April–13 May 1982, 10–30 December 1984, and 19 March–27 July 1985 in Davao, southeastern Mindanao, the Philippines.

This paper first introduces the changes of the Japanese cemeteries in Davao from 1980s to today (29 January 2020). Next, from the researches conducted in various places of Japan such as Okinawa as well as Davao in the first half of the 1980s, I would like to tell about what I couldn’t write at that time, and there are things I can’t write (I don’t understand) even now. And finally, I would like to clarify the reading of the names of Hiroji Kamohara (popularly known as Koji Kanbara) and Gizo Furukawa (popularly known as Yoshizo Furukawa), who are the authors of the two most important books on “History of Davao” written by Davao residents before the war.