Great look at this. They really are something, eh? So much attention to something that most people never see. I first posted about these things over ten years ago. I think I beat the drain spotting book that really introduced the Japanese manhole covers to the world by a few years. If you or any of your readers are interested in seeing more, my buddy Dan of Japanese Castle Explorer once set about compiling photos of every unique manhole cover in Japan. You can find his manhole cover site here: http://jmc.japanese-castle-explorer.com
That's a great resource. Thank you for sharing it here.
In a lot of ways, I think these manhole covers say a lot about Japan and Japanese culture. Just like all the uniforms and the traditional dolls like hina dolls and kabuto helmets, and even like the land-o-sell backpacks that all elementary schools students buy and where to school, this is a way to create specialty jobs, employ artisans, and keep money flowing through the economy. In addition, they add to the uniqueness and character of each area, which is something that I think is really valued over here.