survival japanese (eating out)

My apologies for once again having gone AWOL.  When work is in full force, I seem unable to stem the tide of tasks coming my way, and blog-writing (and other kinds of writing) is one of the first things I tend to sacrifice.  There must be a way for me not to do that, but I haven't found it yet.

ANYway, getting back to it. . .
I was at a kaiten sushi (actually, the correct term is kaiten-zushi) place not long ago, sitting next to a couple of young Americans.  Seemed like nice fellows, clearly on their first trip to Tokyo.  From the sound of it, they were staying at a capsule hotel in Shibuya, lovin every minute of it.

As they finished eating, they wondered aloud what to do about the check, and where to put their empty little sushi plates.  They thought that they were supposed to take the plates to the register, to be counted by the waitress/cashier, for the calculation of their bill.  I said "Oh no, just leave them on the counter and the waitress will come and total everything."  I think the guys were a bit surprised to hear me speak English; since I'm Asian (-American), they might not have presumed that I was an English speaker.   (Lots of the Westerner travelers that I meet in Japan probably suppose that I'm Japanese until I speak.)  They recomposed themselves in an instant and thanked me, and I began to summon the waitress, when it occurred to me that they might like to ask for the check themselves.

     "To ask for the check, you can say 'Okaikei kudasai.'"
     They repeated  "Okaikei kudasai."

I wanted to say and write down for them that kaikei is check, or bill, and okaikei is a polite way to say it, because it didn't seem like they knew it and it did seem like a useful bit of information, but our waitress was upon us in a second.  "Okaikei?" she asked.  "Betsu betsu?  Issho?"

     I asked the guys, "Do you want to pay together, or do you want separate checks?"
     "Together."
     "Say 'issho.'"
     "Issho," one of the guys said to the waitress.  (Betsu betsu, of course, would have meant going dutch, paying only for what you ordered individually, etc.)

And she counted their plates, rang it up on the register, and the guys were on their way.  It's nice to see people visiting Tokyo for the first time.

I should also mention that oaiso is another word for check; I read in a textbook that it's mainly an alternative to be used at sushi establishments (but not at other kinds of restaurants or eateries).

Below is someone's video (from YouTube) of kaiten-zushi, which is often described as sushi on a conveyor belt.  One of the places I often frequent has "Sushi Merry-Go-Round" posted outside, so I guess that would be another way of putting it.