Did you catch the image gallery linked at the top of the article: http://www.theguardian.com/cities/gallery/2015/aug/12/tokyo-without-ads-japan-stripped-bare-in-pictures I way pretty impressed when I was in Japan. Overall the signage there felt less intrusive than in South Korea, or the heavily trafficked areas of the US.
Wow some of those pictures just look how I would imagine the 70's to look like. It is refresing to see, honestly. We have a law here that prohibits advertising on school campuses (at least!) but there are some loopholes too. All our classes are actually replaced by the "sponsor" so I'll often say stuff like "marketing class is at Procter&Gamble on tuesdays". And billboards are just filled with school activities related ads anyway so it's not like we'd have blank walls.