I'm an idiot when it comes to designs. What exactly is Japanese about the Excelsior? Is it the neck?
Excerpt from the Bill George interview on disc 2 of the Star Trek III Special Collector's Edition:
...At the time I was really into Japanese art, especially industrial design...and so the concept I came up with was: what if the Japanese had designed the Enterprise? And so I took the basic layout of the Enterprise and tried to apply a Japanese aesthetic, and it was industrial design from the 80's where everything was getting abbreviated and simplified. And if you look at the dish especially it's much sleeker and more angular...and the neck is thicker and broader, and is more like a fin, like a heat sink, and there's this repetitive detail in it. It's hard to say, like, "Oh, it was based on this exact design." It was more an overall aesthetic. We presented them all to Leonard and ultimately he went, "That one." and it was the Japanese version.