One of my commoner whinges used to be that I could find very little published material describing Japanese derailleurs dating from before the great Japanese invasion of the USA in about 1973. And then I was sent this magnificent collection of scans of 80+ adverts dating from 1963 to 1973. Unfortunately I speak no Japanese and my understanding is based entirely on the surreality-generation-engine that is Google Translator. At least “my hovercraft is full of eels” (which may translate as “私のホバークラフトは鰻でいっぱいです”) has a subject, verb and object.
Back on the subject of the adverts, things that I think I have understood correctly include that:
Things that I am sure that I don’t know include:
I don’t usually include documents on this site that I have not scanned myself, but in this case I decided to make an exception. This is partly because these are adverts, not editorial, partly because, after a reasonably extensive search I could not find them on any other web site and partly because I find them so interesting because they fill a yawning gap in my knowledge of the history of the derailleur.
If you made any or all of these scans, I apologise for displaying them without your permission - but I hope you will agree that they are being used for a good purpose.