Japan Cruise Embarking At Shanghai Port

You are eligible for 144 (72 hour TWOV was replaced with 144 hour TWOV a couple years ago) visa free transit in Shanghai during your first arrival and for 24 hour visa free transit in Shanghai, so you don't need any kind of visa. Anyway, you should just check briefly your itinerary to see whether you fulfill the following conditions:

- Your flight from US to Shanghai is no allowed to have any additional landing within mainland China and Japan
- Your cruise is not allowed to have its first port of call, immediately after Shanghai, in mainland China
- Your cruise is not allowed to have its last port of call, immediately before Shanghai, in mainland China
- Your flight from Shanghai to US is not allowed to have any additional landing within mainland China and Japan

I'm practically certain that your itinerary fulfills the above mentioned conditions, but I encourage you to check once again.

By the way, you don't need to do any kind of announcements or applications before your journey. You should have your flight and cruise tickets in hard copy and you will declare at the check-in in US that you plan to transit China on your route to Japan using 144 hour visa free transit. Your tickets will be inspected and you will be allowed to board the plane. Upon arrival in Shanghai, you will approach the 24/144 hour counter and tell them basically the same story. They will inspect your tickets , you will get a sticker in your passport and you will be allowed to exit the airport.

You will do the same in Japan where you will declare that you will travel to US via Shanghai, but this time using 24 hour visa free transit. The same thing again in Shanghai in the cruise terminal.

Essentially, this is it.