In Japan, there are basically four types of soy sauce: regular dark, light or usukuchi, reduced sodium or genen, and tamari, which are the rather syrupy dregs of soy sauce at the bottom of the barrel. The first two are the ones most commonly used for cooking. Reduced sodium is of course used by people with high blood pressure concerns. Tamari is never used for cooking — it’s usually used as a dipping sauce, for sashimi and such…
Kikkoman makes its soy sauce locally throughout the world (a bit of trivia: Kikkoman is one of the oldest, if not the oldest, food producing company in the world, having been founded in the 17th century). and is also decent in flavor.
You don’t have to refrigerate soy sauce, but do screw the cap on tight and keep in a dark place. And always use sparingly. [Really Hungry]