Tokyo in the 21st century.
The 21st century is the time period that begins on January 1, 2001 and ends on December 31, 2100.
From the 2005 version of Doraemon and onward, it has been retconned that Nobita and his friends are still children in the early 21st century, and as such most of the events take place then. Originally, most of the manga and anime was set in the 20th century (1901—2000).
Nobita, Shizuka, Suneo, Gian, Dekisugi and most of the Doraemon characters live in this century and most of the episodes and many movies of Doraemon take place in this century too. This is the more important century of the Doraemon universe since this century is clearly given more importance than the 22nd century and has way more screen time.
