The instructions show the interesting cable routing round a roller on the derailleur (Simplex used something similar a decade later). They also show the gear ratios when a 17 to 20 tooth 4 speed cluster is used with the 3.3.3. hub gear.
I admire the Shimano 3.3.3. logo and the graphic design in general.
I can’t comment much further as, unfortunately, I do not read or speak Japanese.
Browse associated derailleurs.
Shimano Combi 12 red 1965