I used the package option [hotel + shinkansen + park tickets] on the website. You have to struggle through translate though if you can't read Japanese, and the site is prone to bugging in Chrome and Safari - it seemed best in Firefox [which doesn't have native translate support]. I have since noticed some tours on Viator including the park - presumably enterprising locals making use of having the inside line on getting tickets, along with providing translation. I would probably have used that, but by the time I saw them I was past the 21-day cancellation deadline with JTB so the bed was made.

We arrive Sunday, I have all the QR codes and confirmations which I need to print out today so hopefully all goes smoothly - I will revert to update.