Gravity Rush (or Gravity Daze as it's officially known in Japan) made it into the Media Create top 20 just twice, reaching total sales of just over 50,000 units in late February. It seems that the game has been selling steadily since then and has now topped the 100,000 in some combination of sales and shipments.
Director Keiichiro Toyama said at Twitter today that the game has been selling continuously, albeit in small amounts. Adding retail shipments and download sales, the game has now crossed the 100,000 mark.
This figure is just for Japan and does not include Asia.