We did the same trip 5 or so years ago in December with a large group (ages 4-50yrs) we just broke up our days a bit different.
6 days Tokyo (2 at land, 2 at sea and 1 at Tokyodome) 3 days at Hakuba and 5 Osaka (2 at USJ) no fast passes and didn't stay on site.
We are replanning this trip for 2025 and the changes I'm making are
No side trip to Hakuba. No TokyoDome. No Osaka castle. No Skytree. No Zoo (was depressing)
Staying on site for USJ and adding a extra day.
Staying on a partner property for Disney and adding a extra day or 2.
Adding in Sanrioland, Ghibli Studio Park, Pokemon Cafe.
Last time the size of our group made it difficult for everyone to see what they wanted so this time round our group will be larger but we will split up more so everyone can focus on the activities they really want to do. And also to have some down time as last time it was go, go, go. I needed a holiday when we got home.
JR rail pass is good for the train, make Sure you have roaming or a local sim card to help with directions, help with translation and to get in touch with your group when needed. If your with a large group make a plan/schedule.
Have a great holiday! Look forward to reading your trip report.
