Many guests write that they would like to visit the Imperial Palace.
It's totally different with the Buckingham Palace in London. You can only see the Imperial Residence in this picture.:-) The buildings in the upper middle 御所 near the bridge gate are the three-storied house of the Imperial couple.
There is a free Imperial Palace tour conducted by the Imperial Household Agency, which only see the Public Buildings from the outside and cross the Iron Bridge named Seimon Tetsubashi. Those are the green roof buildings in the lower half middle. You're supposed to move in a group of 200 or so altogether and you're not allowed to leave in the middle of the tour. Nowadays it's shorten a little bit, so after you're gathered, it ends in about 1 hour and a half, but I would recommend my guests to visit Edo-Tokyo Museum instead if you have that time.
https://sankan.kunaicho.go.jp/information/lists/kokyo
I recommend the East Gardens of the Imperial Palace as a must-see. Even there are only several buildings left, because there were so many fires burning down the major buildings, it is the site of Edo Castle, which became the capital in 1603, the Shakespearian/Queen Elizabeth 1st ("Virgin Queen") days. Since then Tokyo began to grow as one of the largest cities in the World.
I would love to explain those things to you and also let's enjoy the beautiful nature in the very center of the Metropolitan Tokyo.
https://gowithguide.com/japan/tour/tokyo-edoeast-gardens-ofimperial-palace-ueno-1713
If you'd like to see authentic Japanese castles, please add Matsumoto Castle and the World Heritage Hi・me・ji Castle on your bucket list. Both of them are amazingly beautiful.
If you'd like to see a gorgeous palace, go to the State Guesthouse in Yotsuya, which is imitating the Versailles Palace (Admission 1000 yen), but are you coming all the way to see a Western imitation?
I hope you come to see something unique of the Japanese.:-)