Thank you for your feedback!
The article is primarily based on personal experiences (in particular, regarding movers, taxi drivers, and doctors) and is not intended to be a research paper. Thank you also for pointing out inconsistencies and misspellings. The incoming typhoon made me rush things a bit yesterday. I have updated a few of the issues you've mentioned and will add another paragraph on shugibukuro.
We have more info on formal gift envelopes (shugibukuro, noshibukuro, etc.) on our page on
gift-giving in Japan.
I'm not sure whether it's illegal for a physician to accept gifts, unless they work in a public hospital. However, in Japan, too, there must be a code of medical ethics stipulating what constitutes an acceptable "token of appreciation" and what does not. That would need more research.
The question of whether tipping has ever been customary in Japan may also require further research. It depends on how you define tipping: if it's simply a "gratuity for a service rendered", then it has probably never played any significant role in Japan. If, on the other hand,
kokoruzuke is considered tipping, then we're getting into the realm of "social lubrication", where a tip is given to secure a future service or benefit. It's just a small step from "greasing the wheels" to "bribery".
Gift-giving has always been an integral part of Japanese society, not just between individuals, but also between companies, individuals, and companies, or people holding public positions, thereby often bordering on institutionalised bribery.
Anyhow, thanks again, Glenski, I really appreciate it!