I live in Tokyo, and there are few places which are more advantageous to owning a folder. The public transportation system in Japan is great, and is very efficient and reliable. It doesn't get you everywhere, but if you bring a bike with you, pretty much every part of the country is within your reach.
After the big East Japan earthquake a couple of years ago, blackouts and repairs affected the train service, and rolling blackouts occurred. It became wise to take my bike with me on the train to work, as it was sometimes necessary to ride my bike home. I was glad to have it at these times.
Folding bikes are very much part of the Tokyo cycling culture, and there are many clubs for fans. Most shops have a good selection of folders, and countless parts and accessories. The Japanese love to accessorize, and as most people don't have the space to keep a car, they often spend a lot money on their bike. I recently saw a Brompton with tooled leather bags, mudguards, grips, and a handle, looking much like the stuff I put on my horse back in my horse-riding days.