Underground of Tokyo station is very complicated, unless you know exact exit, you would be lost, absolutely !
Yes, I was lost before, dear me…
QR code offers you the information around there.

In Japan, these days QR code became popular than last year.
Many websites offer their mobile sites with QR code, and you will see advertisements in a train also place QR code on.
But, it is a bit weird using your mobile phone’s camera in a train, isn’t it ? At least I can’t do in the packed train !!

Related posts:

1. Japanese people can’t live without mobile phone
2. Manin densha…. >.
3. Train Fun
4. Mobile Phone biscuit or Cell Phone Cookie
5. 大富士ゴルフ場