Better Know a Seasoning: Soy Sauce

Soy sauce is one of my favorite ubiquitous sauces that has always been a staple in our kitchen - and every time we buy soy sauce, we buy Kikkoman (are you brand loyal?). They have a nifty & informative website, too:

http://www.kikkoman.com/soysaucemuseum/index.shtml

However, despite my love affair with Kikkoman over the years, it was only recently that I noticed this on the back of my beloved bottle....

Does anyone actually refrigerate soy sauce? Does it really improve the quality? Also, what the heck is a "sase"?? (Top right hand corner of the label)