I know just enough Japanese to get by if I get lost and greet an audience properly, just from having a lot of Japanese friends and being there over the years.
The more business one has, the more you are able to accomplish, for you learn to economize your time.
There is absolutely no one, apart from yourself, who can prevent you, in the middle of the night, from sneaking down to tidy up the edges of that hunk of cheese at the back of the fridge.