I love this about the Tokyo Metro. Chilled water available on tap, free, on the platform. Sparkling clean bubbler (water fountain) - no cigarette butts in the bottom, no left over chunks of vomit, no grungy bits that make a person recoil with fear of communicable diseases. As part of my eco endeavours, I'm taking my water bottle almost every time I go out. Great effort Tokyo Metro, may others follow suit.