Great idea, but not sure how practical it'd be. It'd definitely be a talking point, especially after a few glasses… 

I'm also not sure how much it will cost to buy.  I'm thinking that John Lewis would sell this sort of thing, and it wouldn't be cheap.

Looking at it a bit more, the potential for drinking games utilising this glass is huge.  In fact, I definitely want one now.

You can find out more about this and other great product designs on Kyouei's website.