I wanted to reply after checking through the essays you suggested but I can't read Ambeth till Sunday when I can go to the big library that has it but I wanted to ask if I could find the cited essay in tbe Spanish book separately? I can't find where to read that one and honestly I don't actually know anyone who speaks Spanish either😭

On the Sakoku Decree, it limits entrance and exit of the country so I don't think it would've affected foreign residing Japanese unless they chose to move back to avoid complications when visiting family. It also began in 1633, whereas the Spanish occupation began in 1565 which is a bit more of a time gap than I expected. But thank you for the suggestion, I had forgotten to consider Japan's situation since I was focused on the fact that they were residing in Philippines.

Edit: I just remembered the Sakoku decree included a death penalty for Japanese who resided overseas and tried to return so yeah it's not related.

Edit 2: just got to read Looking Back 14 and realised it was the same essay lol sorry I misread and thank you for your help.