Also Japan is the world leader in fax technology. Fax. Many fax companies are only viable because of the Japanese market.
It's mostly because Japan is bad at web technology and APIs though. They also love gratuitous complexity; you've seen their websites and how every page is covered in stuff, but the URLs themselves are less like "youtube.com" and more like "blahblahblah.bsd.unix.nicovideo.jp/several/tech/buzzwords.jsp".
Asking because I had a bank account for almost a decade now, and I only had to use the checkbook twice, and it was pretty niche use-cases. I still have the same checkbook that I got back then, and I think I won't be able to go through the entirety of it even in multiple lifetimes.
Cannot comment on how widespread the usage of fax in Japan (since I haven't lived there myself), but, from what I heard from other people, you pretty much need to have access to a fax machine.