In which country were square or “cube” watermelons first developed and grown?

I've never seen one before so nice to have a picture!

rayvan, Japan doesn't need to export them. Anyone can grow them. Just put a plastic cage/box around them when they grow. The Japanese might have refined it a bit, but it is a simple idea.

a square meal

inspired! will grow some next summer ☀️

Nada, why are they inedible?

Cool a square watermelon...Won't roll off the counter!