The Kyoto native had been awarded a sponsors' invite for the Sept. 11-17 event at Tokyo's Ariake Tennis Forest Park, Kyodo news reported.
Date, who initially retired in 1996 but returned to competition in 2008, spent 16 months on the sidelines following a couple of knee surgeries before launching another comeback in May.
A four-time winner of the tournament when it was known as the Japan Open, Date will be joined by compatriots Naomi Osaka, Nao Hibino, Risa Ozaki and Misaki Doi in this year's edition of the tournament.
Date won her first Japan Open title in 1992, the same year defending champion Christina McHale of the United States was born.
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(Reporting by Amlan Chakraborty in New Delhi; Editing by John O'Brien)
