Doraemon is a blue robot cat from the 22nd Century, built at the Matsushiba Robot Factory on September 3rd, 2112. His serial number is MS-903. Robots his type help their owners in their daily lives. Doraemon is sent back to the 20th century by Sewashi to help Nobi Nobita (his great-great-grandfather) so his descendants will have a prosperous future. The time machine he travels on is connected to Nobita's desk drawer.