Helmet to prevent head from tilting while sleeping on train. The message board shows the station name for people to wake you up on time.
This whole post is scans from a book that came out in the 90s called…uhhh…I think it was “100 Unuseless Japanese Inventions” and “100 More Unuseless Japanese Inventions,” which featured inventions by the “International Chindogu Society” (Chindogu being a weird portmanteau of a slang term for dick [chinchin] and the word for tool [dogu], if memory serves).
The book featured tons of stuff that sort of made sense but was also impractical - things like this helmet which serve a purpose but would be bothersome to carry around and actually use, for instance. THE BEST PART is that I have seen plenty of chindogu ripoffs in SkyMall as an adult - one example being flip flops with nails on the bottom, which you would walk around on your lawn with to aerate the soil. THEY TOTALLY MAKE THOSE NOW.
In the back of the book they had applications to join the International Chindogu Society (was it ever a real thing or just an invention of the book? I should look this up) and the only requirement was to submit an invention idea. I came up with a few…the only one I remember was a huge salt shaker that was the diameter of a plate of food so you could salt an entire meal evenly at once (in theory).