Thanks for the information! I found the area on my map.
Since Nagoya was so heavily bombed during World War II and I've seen very little construction that isn't postwar, I'm intrigued to learn that there is a historic district so close to the main train station.
I don't really need an English-speaking guide, since I earn my living as a Japanese-English translator, so next time I'm in Nagoya (whenever that is), I'll see if they have any information at the station.