I was initially confused since the term "Chindogu" isn't actually that common in Japan, but it turns out it was an artistic movement led by Kenji Kawakami.

https://en.wikipedia.org/wiki/Chind%C5%8Dgu

While they are humorous, it's a serious artistic endeavor at its core, so it's not exactly "laugh-out-loud" funny. I feel like there are much crazier inventions in Japan—I wish I could think of some specific examples to share right now, but nothing is coming to mind at the moment.

One "interesting" invention (that might have seemed a bit silly at first) is fan-cooled workwear. With Japan’s summer temperatures now constantly hitting 35°C (95°F), what started as a quirky idea has become an absolute necessity.

https://kuchoufuku.com/

There’s something inherently funny about the models in the link posing so seriously while wearing clothes that are completely puffed up with air.