Umm.... I dunno. My mother is a Chinese immigrant. I was born in the U.S. But, like... she has a really thick accent and terrible English grammar. In fact, so do my uncles and my grandmother and probably about 90% of the Chinese, Koreans and other people from Southeast Asia that I've met. Admittedly there's that other ten percent who have terrific English, despite learning it late in life.
Though, I will admit the accent used by the people in this isn't really quite right... it's not quite Chinese and not quite Japanese, it's kind of got elements of both. Maybe a little like Korean, but not really quite like that, either. But they are from the fictional country of Madripoor where they have their own fictional accent.

I think the monotone delivery is meant to be reminiscent of the detective noir genre, where the internal monologue was frequently deadpan and the protagnist unflappable.At last thats how I saw it. So far I have rather enjoyed it. The story is interesting.