Twenty-seven players out of the current world top 30 will take part in the two-million-dollar hard court tournament from September 26 to October 2, with only Kim Clijsters, Venus Williams and Justine Henin missing.
Sharapova captured her first WTA singles and doubles titles at the 2003 Japan Open, and also won her first professional title on the ITF Circuit series in Gunma, north of Tokyo, a year earlier.
The Russian heart-throb has won four titles in Tokyo out of her 22 WTA titles, including the Japan Open twice and the 2005 Pan Pacific.
Last year, Sharapova put an end to a long lay-off caused by a shoulder injury by winning her first title since Amelia Island in April 2008, beating Jelena Jankovic of Serbia in the final.
Along side world number one Serena Williams, the singles field includes former Pan Pacific champions Elena Dementieva of Russia, the Beijing Olympic gold medallist who won here in 2006.
Other former champions are Japan's Kimiko Date Krumm, the winner in 1995, and Dinara Safina of Russia, the winner in 2008. Both picked up a wild card.
Petra Kvitova of the Czech Republic and Tsvetana Pironkova of Bulgaria, who caused a sensation by reaching the semi-finals at Wimbledon, will make their Japan debuts.