Kikkoman Soy Sauce does not need to be refrigerated after opening, but it's essential to store it properly to maintain its quality and flavor. Soy sauce is a fermented product, which means it has a high salt content that acts as a natural preservative. As long as you keep the bottle tightly sealed and store it in a cool, dry place away from direct sunlight, it should be fine at room temperature.
Refrigeration is not necessary, but some people prefer to refrigerate it, especially if they live in hot and humid environments, to prolong its shelf life and prevent potential spoilage. If you decide to refrigerate it, the sauce may become slightly thicker or develop sediment, but it's normal and won't affect its taste or safety.
Always check the label or the manufacturer's instructions on the bottle for any specific storage recommendations. If you have any doubts about the quality or safety of the soy sauce, it's best to discard it and get a new bottle.