On my huge bottle of Kikkoman soy sauce it says very clearly: "Refrigerate after opening." And yet I don't. My Asian friend, an amateur chef, never does. I go to Chinese restaurants and there is soy sauce sitting out on every table.
So what's the deal? Are you supposed to refrigerate or not? I did a little research and discovered that soy sauce is fine at room temperature. It's just that it will keep its flavor and freshness longer when refrigerated.
Kikkoman does say on their soy sauce product page that it should be kept in a cool place. You can read more about soy sauce and the way it's made at Kikkoman's soy sauce Q&A.
What do you do? Refrigerate? Or does it sit out right next to your wok?