Here's the jingle that stayed with me, even when I forgot all useful Japanese.
It's that very last bit when they say "sou-ken-bi-cha" all sing-songy.
While I'll drink a Coke with my Big Mac, when I am actually thirsty, I just don't really feel inclined to drink something carbonated or sugary and often opt for water. I love water. Seriously. Back home, it's what I drink most because we don't have Soukenbicha. To me, Soukenbicha is kind of like water - clean, clear, refreshing, no calories - but then with a nice mild and not even really "tea-like" flavor. It's good stuff.
I sound like a commercial. They don't know or care who I am, but I am madly in love all that is this amazing drink. I'm not alone. It's even on the menu at McDonald's. Of course, most everyone where I'm from knows that you can't drink water/water-like drinks when trying to wash down your burger and fries because you need that carbonation to make the grease not stick and the calories not count (it's a Maggie Math thing, never mind, carry on), so then it's Coke, all the way. Soukenbicha or water (or mugicha) are for me for all those other times I want to be refreshingly healthy and amazingly beautiful, though.