I am having trouble enjoying these books because the combination of cultural/ethnic stereotyping and lack if research is mildly offensive.
In the last book, the Asian gang member discussion was peppered with Asian puns, mostly Chinese. Those gang members have turned Vietnamese, although they have Chinese names.
They call the Mexican gang members "Cholos." Really?
The book is centered around a Japanese restaurant named "Red Dragon" that serves tea smoked duck as a specialty. REALLY?
Basically, the impression I get is that gang members must be identified as being "foreign," but once something is "foreign" further distinction is unnecessary. So, using Vietnamese puns for Vietnamese people (or names, for that matter) or having a Japanese restaurant actually serve Japanese food (or have a Japanese name) is all unnecessary. Besides, Chinese and Japanese are basically the same thing anyway, right? And Vietnamese. All Asian. Who can tell them apart anyway?
(Hint. Search "Red Dragon Restaurant.". You'll get tons of hits, it is a popular name. FOR CHINESE RESTAURANTS. WHICH IS WHERE YOU MIGHT EXPECT TO FIND THE CHINESE DISH "TEA SMOKED DUCK.")