

It’s a better product idea than you make out.
It does require industrial design, and tooling for flexible panel manufacturers to make umbrella patterned panels, as cheaply as rectangular patterned ones.
Flexible panells top out closer to 25% efficiency than 20%. 200-250w is a lot of power. The umbrella itself needs just a hook for a battery rather than coming with one. Solar or USB (up to 240w at 48v power) interfaces. This can power a mini pc with a couple of large monitors with power left over. 1kwh per day/m2 is enogh to cover a high power laptop, electric cooking, or if it were a beach parasol, keep a drink fridge cool, and boom box TF out of the place. Because you need an ebike to lug all of the crap to the beach, it can charge it back up. Besides beach use, a parasol would allow supplementary power for van/RV or even a house, when not beach party boomboxing.
Japan is not known for having any/many immigrants, as it is. Expats generally avoid it for high cost of living.