Last night I drank with one of my ex-coworkers to celebrate her graduation from university and resignation from her part-time job for 4 years.
And there, you know I can't drink, I ordered "有馬サイダー (Arima Cider)".
Arima Cider, or Teppo Water, is a popular drink in Arima Onsen in Kobe (→http://www.arima-onsen.com/eng/index.html)
On the label it states that carbonated water gushing from the ground had been thought to be poisonous and been afraid of, but later served as the origin of Japanese cider.
I think it's a robust soda with less sugar.
Showa flavor and taste!! (^o^)