Lived in Japan for 4 years:

  - yes you need to speak and read Japanese
    - a lot of sites embed the information inside of images, not text, which is not that easy to translate automatically and your AI agent probably won't think to check it unless you use screenshot navigation by default
    - a lot of the booking will be done or expedited by phone calls
  - yes you need a Japanese phone number
  - yes you need a Japanese debit/credit card most of the time for online systems (or pay at the conbini, aka physical locations in Japan, American credits cards also work usually)

Japan is what it is. It's not super friendly infrastructure if you're not living there. No they don't want to change it.