Pink Tentacle site likes to find Japanese ephemera – often disappeared for a while, but sparking curiosity again now. It's current selection of proletarian posters from the '30s is interesting. (The Communist Party is still fully-functioning in Japan, unlike in the UK, for example – standing in the upcoming elections, debating on TV with other leaders. A perhaps unexpected detail about Japan.)
The site's intro is a little simple: "In the 1930s, as the masses came to dominate Japanese society". (Ah, that'll be the masses that then took Japan to war.) And mentioning the "Western" design influence is also a tad questionable. The obvious design influence is Russian – a country which neighbours Japan as well as continental Europe. (Is Russia "east", "west" or "Russian" or…?) Little niggles: the site's selection is excellent.