Hi. I am Yuhei. It is still hotter than the Tropics...(^^;;)
How are you?

Water is essential for anyone. How can you get in a foreign country?

Sometimes I was confused in front of a lavatory with thinking as " Can I drink this tap water directly?" The answers were sometimes YES, sometimes NO.When I lived in Indonesia, it was strictly prohibited to drink everywhere, and the Thailand was also same. In fact, I took a shower everyday in Indonesia, and the more and more my skin was damaged for 2 years. I am annoyed by the skin sickness from then...My skin under the chin always itchy.

Do you make your hand dirty or clean?

In Japan , you can drink tap water everywhere. It is verrrrrrrrrrry goooooooooooood point of Japan, I guess. Please assume that you are washing your hand with tap water which cannot be drunk. It is PHILOSOPHY. I would like rather to say that "Washing your hand, and your hand has two surfaces." haha

I was usually confused in Airport when I came back from Indonesia. Can I drink it? After seeing the clean water, I really arrived at Japan. The water is not colored brown as if beer, does not smell like XXXX.

Anyway it is useful for all the tourist from out of Japan.
You can drink tap water.

Quality differs from place by place.

I don't know much about foreign countries' drinkable tap water but I can say the tap water in local areas are so nice. Sometimes its quality may exceed any of bottled water. Of course there are some rubbish ones. ( I feel the worst is tap water of big cities such as Tokyo, Kyoto, Nagoya, Osaka... )

Let me suggest one of the best quality tap water in Japan. That is the Kakitagawa River springs in Shizuoka. It really moved my heart.

http://www.town.shimizu.shizuoka.jp/toshi/toshi00054.html

That is purified via Mt.Fuji's deep forest. This springs is in the Shimizu town.(Shimizu means Pure water) You can see the bottom of river from on the cliff. Its deep blue is quite beautiful, and impressive.

I can suggest you to look for some destinations due to water, in your next trip in Japan.

Thanks.