Sudah ada trip report #3151, didn't read meh....

Lol! People write itinerary based on their interest, why not find out what ur interested to see, experience, do?
Just start with a guide https://www.japan-guide.com/

Only becareful not to try and do everything that's listed down.

If you see some of these people scheduling, you will go crazy. Hahaha! Some prefer to touch n go then rush to another spot, others might spend half day at the same places. So their itinerary can be quite varied in scope.

I suggest you use the subforum search function to read on their schedule and shared views. That would give you a good picture of what you want to see and which that you can skip, and how long you would think to stay at a location.

P.S Always plan for 1-2 extra places at a nearby location you would optionally like to go if you have the time. That way if you get bored early with one spot, you can still visit another place within ur budgeted time.