Japanese websites often seem really busy to me. I'm not fan of narrow strips of content with excessive whitespace designed for cell phones but too much information/link/image density and it's overwhelming.
One analysis I’ve heard of that is that Japanese is naturally a more dense language than English or other European languages, so the style seems more natural to native readers of Japanese.
There may be more to it than just that. Japanese culture seems to value really busy spaces. Frantic pop music, blinking lights, and all that. Possibly not coincidentally, the most popular recreational drug in Japan is meth.
Apparently there's a whole subset of Japanese only websites that still use web 1.0 design considerations.
I've been tempted to learn Japanese just so I can experience the joy of being frozen in the 90s.
If it ain't broke, don't fix it.