this guide was primarily made for buying music from japan, but it will probably be useful for you.

https://meramifan.wordpress.com/guide/

There are forwarding and proxy shopping services that solve this exact problem of japanese shops requiring a japanese address.

https://meramifan.wordpress.com/guide/#forwarding-and-proxy-shopping-services

I live in Japan how can I help?

I don't live in Japan but I do have a product I bought that includes a Japanese Audio Drama. I was planning on posting it on here later for my private use. If I can send you a private invite for it here I will.

I may not do it in a timely manner and be sure to remind me.

Audible and Bookwalker don't seem to require an address.

If you are looking to post the E-Books here. I suggest using https://www.aozora.gr.jp/ which is the Japanese equivalent to Project Gutenberg, which are books available in the public domain.

You can buy from Amazon JP, but you have to use a VPN and give the address of a hotel or something similar. I know of people who used the address of the Hilton Hotel in Tokyo for instance and it was fine.

You can also use a proxy address service such as Tenso. They will provide you with a virtual Japanese address and you'll be good to go.

There's also Kobo Books Japan that doesn't require the use of a VPN but still requires a Japanese address.

I think Kobo is a better choice, because the DRM is much easier to remove if you want to import these books into Lingq.