There sure were U-Boats operating in the far east. My friends of U 181 operated there from sometime in 1943 to wars end. There were several other U-Boats in the east too such as U 191. At wars end, U 181 became property of the Japanese Empire and was renamed I-501, I believe. I-501 was later lost or scuttled at sea.

When U 181 became Japanese property (as afew othey U-Boats did) the crews were inturned in camps just short of prison, by their Japanese allies.

Two excellent sources for more info of what happened to U-Boats in the far east are: "Shooting The War" By: Otto Giese, and the German U-Boot verlag book vol. 4.

As for German Land and Air force personnel serving in the far east, there were attaches, but I don't think any sizable units that I know of.