The drive will go on sale on March 11 and will cost ¥15,540 (US$172).
The unit has been available in the past as part of package deals, but never before as a stand-alone unit.
Microsoft has no current plans to put it on sale as a stand-alone unit outside of Japan, said Kei Iwasaki, a Microsoft spokesman in Tokyo.
The drive is used to store downloaded software, TV shows, movies and other content from Microsoft's Xbox Live Marketplace online store.
Rival Sony recently re-launched its PlayStation 3 console and includes a 120GB drive.
Last week Microsoft announced strong earnings, primarily on its Windows 7 roll out in the past quarter. Xbox 360 and PC game revenue dropped by 12 percent, or $295 million, however.