Crystal Tokyo is the city that replaces Azabu-Juuban in the future.
A new Silver Millennium will exist in the 30th century, centred in the city of Crystal Tokyo.
Usagi and Mamoru will rule Crystal Tokyo under the names of Neo-Queen Serenity and King Endymion, and they will have a daughter named Princess Usagi Small Lady Serenity. The Earth becomes a world wide kingdom once again.
The Guardian Senshi protect the entire royal family. Sailor Pluto guards the space-time door. At the centre of the kingdom stands the Crystal Palace, where the Royal Family, the Guardian Senshi, Luna, Artemis, and Diana live.
Exposure to the Silver Crystal renders all of Earth's inhabitants functionally immortal. Anyone not born in Crystal Tokyo becomes essentially locked at their current physical age, as shown by the Queen, King and the Guardian Senshi court, who all appear as if aged in their early twenties. Anyone born in Crystal Tokyo has a slow growth-rate.
There was a sudden unbelievably big explosion in Crystal Tokyo and everyone except Chibiusa collapsed.