One thing that I do not buy in this movie is Christopher De Leon’s character. I just can’t make myself believe that such a person exists during those times. It would have been perfect if the character is 100% Japanese (or a half-Japanese but played by a Japanese actor or even by a Japanese-looking actor).
Half-Japanese, half Filipinos existed in those days; Japanese workers were brought in to work on Kennon road, among other American projects. I've met quite a few of them in Baguio, and they keep close ties to Japan, even getting scholarships to Japanese universities.
(edit) forgot to mention that Japanese Christians were expelled from Japan in the 17th century, some of whom settled in Manila. The Paco area was known as "Yellow Plaza" because around 3,000 Japanese lived there. They've been around, and intermarrying, for longer than I realized.
I don't think much of Boyet as an actor--not dumb, but not exciting--but I thought this was his finest, most complex performance ever.