Japanese overdesign is not only about removing inconveniences, it's also about bringing a bit (or even a lot) of joy into using seemingly mundane products - just like this highlighter. Just knowing that a lot of thought went into the product to make it as good as it can be without making it a luxury item is something that elates me whenever I use something like this.
Another good example is Japanese cling wrap, which is just so much better than everything I've seen in western supermarkets.
> Japanese cling wrap
Careful with this one. As I understand it, most consumer cling wrap in western markets is polyethylene film, which is made without plasticizers. But Japanese cling wrap (and the stuff at Costco) is plasticized PVC film, and those plasticizers may well be soluble in your food. The market is supposedly shifting toward safer plasticizers, but I personally would rather not place soft, plasticized plastics in prolonged, direct contact with my food.
I watched a video about Japanese cling wrap, and it showed the box has a plastic lip on the part of the lid that's used to cut the film at the desired length. Here in Europe all the rolls I've ever bought came in a paper box which just had a serrated paper edge that gets dull after using it three times (which is not surprising because paper bends easily). I think that probably makes a bigger difference than the material itself. Eventually I got a plastic case for the wraps and I just throw away the cardboard box, but I know most people here use the paper box and would probably be amazed if they tried the Japanese one.
From what I've seen, the Japanese have a very different approach to design. The beauty is always so understated. It's not announced, but discovered by discerning eyes. You see it in their pottery, joinery, clothing, paper, architecture, etc. A lot of their stuff looks really bland, but when it's stuff you care about, you really feel the thought and craftsmanship that went into it.
It also brings me memories of Japanese calligraphic art and the careful use of various sizes, shapes and textures for brushes, where even the smudges and splatters are deliberate.