No. no. It's been around for a very long time, might even date back to before the war, certainly been popular since the 50s.

Practically every soft drinks company has their own version (there's even been a a few Fanta versions - watermelon, cantaloupe, green melon, you name it) and there's also cream melon sodas available.

Best way to experience melon soda is on a very hot day with a scoop of vanilla ice-cream on the top (it's the only way I'll touch the stuff - works much better as a junky, but refreshing dessert than as a beverage IMO - my Japanese husband loves melon soda and has been sharing ice cream floats with his grandmother since childhood)

Next time you're in Japan, look at the vending machines more closely, you'll find lots of varieties of this popular drink.

If you can find Japanese stores near you - it's possible you might find it in a refrigerator somewhere, especially once the summer is in full swing.