Nippon Post "Kami" (Hair) by Kokei Kobayashi

NIPPON POST on  20 April 1969, as part of their Philatelic Week Series, issued a First Day Cover stamps entitled "Kami" (Hair). The illustration was created by Kokei Kobayashi ( Kobayashi Kokei) (1883- 1957) who was a Japanese Nihonga painter.

I find it interesting a stamp called "Hair" was printed with a semi-nude woman as the model. It all seems to allude to the 60s era of long hair and the Broadway play called "Hair". Although the artwork was painted many years ago, I find the timing uncanny. I wonder.