In my case, the meals were long and mixed with alcohol. It was like a "tasting menu" type of restaurant, with the booze proof increasing, as the evening wore on.
Lunches are a different matter entirely. They would wolf down their meal in ten minutes. Not a drop of alcohol, until the day was done. Lots of energy drinks; even before the US had them.
I also drink a lot of alcohol with my meals, but I find that often Japanese people who eat with me refrain from ordering alcohol because the next day is a work day - so Fridays will be a day that everyone orders alcohol for example. I have also been in the accompany of plenty of Japanese who get "Asian flush" and a worried about any effect on their health.
In comparison Koreans will nearly always drink alcohol on a daily basis and to a stronger concentration than what Japanese drink - even the Koreans in Japan.
Lunches are a different matter entirely. They would wolf down their meal in ten minutes. Not a drop of alcohol, until the day was done. Lots of energy drinks; even before the US had them.
Aaahnold made some money, doing Japanese energy drink ads: https://www.youtube.com/watch?v=XRLe826lyao