Unfortunately I don’t know. We saw people touring but in Japanese. We just walked the area. There is an app for Tokyo & it may have information.

Nice to hear that you are visiting Tokyo. It is inot a good place to go when it is raining. Hope this is helpful.

The east gardens are free and you do not need to take a tour to get in. I think there is a small entrance fee. And the gardens are not open every day. Check with your hotel. I am sure they can tell you what days the gardens are open

I would think that a trek through the palace grounds would be a rather nice and relaxing break from the concrete jungles you'll encounter elsewhere in the city. There's plenty of nice buildings to go through right across the street, the National Gallery of Modern Art being a nice choice.

The inner grounds of the Palace are generally not open to the public. only on January 2nd (New Year's greeting) and December 23( Emperor's birthday). You can get a guided tour during the rest of the year, although no buildings are entered. They need to be reserved in advance through the Imperial Household agency and are held in Japanese and English. The Imperial East Gardens are open throughout the year except on Mondays, Fridays and special occasions.

There are 3 entrances to the East Gardens of the Imperial Palace, Ote-mon gate (south-east side), Hirakawa-mon gate (north side), Kita-kikyo-mon gate (north side), and you can enter/exit from any of these 3 gates. So if you want to go through the garden from south to north, you can enter from Ote-mon gate (not Kikyo-mon gate), then exit from Kita-kikyo-mon gate or Hirakawa-mon gate. As far as I know, Kikyo-mon gate (south side) is open only for people who are booked for the tour of the Imperial Palace, which is free and you can book online via Imperial Household Agency.

Other answers give the right info

The imperial palace has different gates but only the east garden one is open for public