Good point…although it is a reference point for Mutual overall.
For what it is worth some sake are exclusive to East Coast (regardless of whether it is Mutual or Meimon Shu/Prestige), but Shimeharitsuru Gold can be ordered in Northern California, and since the Junmai Ginjo is widely available in SoCal, it should in theory be orderable through Mutual. If not, a restaurant could find ways around this, and say, order from SF Bay Area (via Mutual’s other office by a different name) and have it shipped to LA.
There are some sake that are exclusive to the LA market, but one could also order from LA somehow and have it shipped to SF.
If you want to taste such sake, there are ways, and you have to know the right people who are willing to do it and decide it is worth to put those sake on the menu (or in retail). For example, Shibumi has someone who personally drives to Den Sake Brewery to pick up their order of sake and back, just so that Shibumi can carry Den. The brewery otherwise would not deliver (and definitely will not ship) to LA.
If I were say, the sake somm for Hayato or some other restaurant that really puts thought into creating food that pairs perfectly with sake, I would go out of my way to source the right and best selections for the sake list, even if out of the box and obscure, and not available for the West Coast market, provided that it makes the best sense and pairing for the customer (and also for the price), and there aren’t substitutes for those choices. Not everything that way of course.
I need to bring a few of my favorites next time to LA and go to town on CorkageVille!