Heh, as you know I've made plenty of colorful posts on this just look here and elsewhere for "oriental" AND "weigel", I'm sure you'll find something.
If you don't I'll list some of my feelings after trying for years and getting burned. BTW, I bought everything with the name Oriental Adventures when the ink was still wet until experiencing the Rokugan fusion of the early 2000's at first thinking (hey, give it a chance and then falling flat on my face with more junk books).
1) The Osprey and Palladium (yes, I sometimes forget to reiterate that Palladium have good illustrations even Siembieda isn't that bad artwise so the historical ones excel in this manner) books on strict orient (ninjas, etc) are probably your best bet instead of anything with the name D&D attached.
2) Zeb Cook was/is a dweeb at heart so if they had more anime back then he would have injected it however that was not necessarily true at the time. I love oriental culture (fuck, I even love Middle Eastern culture!) but not when its viewed from the view of Lawrence of Arabian type "YOU don't understand THEM like WE do" crap/19th century upper class Victorian "loveliness"/National Geographic "exo-pretensious" /, etc. Some examples of this are
"martial arts" are from Asia and added to the combat system instead of being sublimated in the normal combat options.
3) No fantasy like Europe. No "rust monsters" or full fledged fantasism of concept. An example of this latter in my campaign is that the ninjas are a huge class of monsters akin to giant class. Its sounds hard to wrap your head around at first but thats how ORIENTAL should have been. Not a straight up gazetteer of Earth but the mythical fear of the ninja as monsters first and false impersonators second.