Cheerful drink

Can you guess what the liquid inside the glass is?  Today, I’m not writing about tea.  

It is sake!  Japanese rice wine, which I had at a restaurant.  A waitress brought an empty glass to my table and poured sake into it from a big bottle in front of me.  As you might have noticed, there is a square wooden cup underneath.  She filled the glass up, but didn’t stop pouring immediately.   Some sake overflowed into the wooden cup.  What is this all about, and how do you drink it? 

You sometimes see this way of serving at some restaurants and bars in Japan.  Filling the glass to the top rim can be considered as generosity of bars.  The overflowed sake in the square is bonus.  This is not a formal way of serving sake, but I love this playful service.  When I see the glass in wooden cup, I always look at the manner of pouring with a greedy eye for how much bonus I can get, hehe (^^;; 

Since this way of serving is not decorous, there doesn’t seem to be a proper way for drinking it.  Some people drink it separately from the wooden cup and the glass.  Others take some sips from the glass to make a room first, and then transfer the bonus back to the glass.   Anyway, it is a cheerful moment at a Japanese bar.  I enjoyed it with good sashimi (sliced raw fish) and sushi.  This is sea urchin sushi (^0^)/