(For the curious, you can watch the one I'm watching for free on-line at hulu. "Zatoichi's Revenge". The 10th in the series, from 1965.)
I did a little cursory googling and noticed some other references to it in literature and theater.
In ancient Japan, was this customary for masseur's to walk around blowing a whistle to advertise their services? (And were they generally blind? By this I mean... did blind people generally take up massage as a way to still make a living by touch, or did people seek out blind masseurs for comfort and privacy... or both etc.)The blind masseur wandering the streets by night, blowing his eerie high-pitched whistle to announce his availability for massages, is frequently used in films to set a mood of strangeness.
It just seems like one of those little interesting historical tidbits that would be nice to know.