I like sake too (i'm 16, nearly 17
). It tastes quite similar to sherry, I think. I heard that in Japan, you can buy sake in pre-metric measures; a cup of sake equals 1 goh (合) or 180ml, and a standard bottle holds one shoh (升), which is 10 goh or 1.8 litres.
Just so you know, in the UK (my country), you can order a beer, wine or cider at a pub if you are eating a big enough meal, once you're 16 (it's true!)
.