Melon Soda: a Japanese thing?

The sixth of every month is Melon Day メロンの日 in Japan. I have wanted to write about it each month for the last year, but I keep forgetting to take a photo of a melon! Thing is, I have definitely taken photos of melons over the years, but when I use the search function on Google Photos, it can't find them. Even if I use the American terms cantaloupe or honeydew. 

So, instead, today I thought I would write about Melon Soda as I can find some of my Melon Soda photos. But then I went down a rabbithole, because while looking a few facts up, I came to realize that Melon Soda is a Japanese thing. It is most widely associated with Japan, but reportedly been adopted in other countries such as Taiwan and South Korea.

I don't know where I thought Melon Soda was originally from, but I didn't for one second think it was Japan. I had assumed Japan had adopted it from somewhere! Now that I know it is mostly a Japanese thing, it explains the prevalence and popularity! Did you know it started in Japan? Can you get it in your home country?