I have a lot of German in my family heritage.
On my mom's side, her grandparents spoke only German. Her mom, and my grandmother's maiden name was Wuensche (if you ever went to Spring, TX, you probably know of the Wuensche Cafe, apparently the same family). From what I was told, they were ostracized during the war due to their German heritage. Her dad was in the Navy. The stories that I was told had him boarding a ship in San Diego in 1944 when he received word (a telegram, perhaps) that his second daughter, my aunt, had been born; and in a bit of a contested story, surviving sinkings of two separate ships that he served on. I say contested because my mom claims that was not the story while my aunt insists that is what he told her. I've never been able to locate any records to verify any of that account, possibly due to the big fire back in the 60s-70s in the St. Louis facility where those types of records were stored.
I once made a very serious mistake shortly after I graduated from A&M. I bought a new Toyota and parked it in his driveway. He advised me that I was to move it to the street immediately and that I was to never park it again in his driveway. That was some time in 1991, so even after 50 years he still harbored a lot of negative feelings toward the Japs. And yeah, he referred to them as dirty Japs. Still, given his experiences during the war, I can certainly understand why he felt like that. I even asked him once that had he gone to Europe rather than the Pacific, would he have come home with similar feelings toward the Germans (despite his German heritage)? He thought he would have.
My dad's dad was apparently a tail gunner on a Navy torpedo bomber (TBF Avenger). But like with my mom's dad, my information is third-hand with no real ability to verify anything. I found out about the tail gunner thing at his funeral. What I do know is that he was in the US Army prior to the war, and had served his time there and received an honorable discharge to resume whatever his normal life was. He then enlisted into the Navy after Pearl Harbor. In another point of contention, my dad thought he was sent home due to a serious illness pretty early on in the war, whereas records that I found suggested that illness did not happen until much later in the war. I'll lean toward believing the latter given that my dad was only 4 when the war started.
Neither of these men ever volunteered anything regarding their war-time experiences. With my maternal grandfather, there was some long-lasting resentment toward anything Japanese; I never got that from my paternal granddad. But he never spoke about the war. I've had a life-long fascination with WWII, particularly with the aviation part of it. I was three years old when I first put together a model airplane, a P-40 Flying Tiger. My paternal granddad once took me on a weekend trip to Houston, where we got to stay in a hotel in the Galleria area and I found a plastic P-38 Lightning in the room when we got there; and after my parents' divorce, we lived with my maternal grandparents for a time - I had a bunch of model planes in that room that I know my Papa was aware of. That was roughly 1976, if I recall right, and we always watched the show Baa Baa Black Sheep - my Papa sat there in his recliner, never saying a word but one could kinda tell that he was not particularly fond of what he was seeing. Given all of this, I used to wonder why they never talked to me about WWII, but now, as I've gotten older and have come to understand more deeply what these men experienced, I wonder why I did not approach them with questions. Really wish I had done so, as I do believe they would have talked to me about it.
Had other, more distant family, who served. One leaped out of a perfectly good C-47 over Normandy in June 1944. He survived and became one of our family's more amusing uncles (this guy insisted to my sister and I that chocolate milk came from the brown cows, with a wink to my dad, when we were roughly 5 and 7). One may have been a bomber crewman in Europe, so either B-17s or B-24s from the little information that I have. And then there was one, my paternal granddad's brother, who was KIA at St. Lo, France, in July 1944.