If you’ve arrived by the Shinkansen in Nagano then I can almost guarantee you’d have seen Beck’s even if you don’t remember it. Beck’s is the coffee shop next to the tourist information centre just across from the Shinkansen entry and exit gates.
I’d wandered in looking for a coffee but they had a breakfast special on that would give you a small bacon, eggs and toast along with a coffee for ¥390! And that was including tax!
The coffee was reasonable, as were the bacon and eggs.
If you’re waiting for a train, and you don’t want to wait on the platform, you can wait here while you have a coffee and snack, and all train departures are shown on a couple of TVs on the wall so you won’t miss your train.
Certainly not the best coffee in the world, but it did the trick to wake me up.