The Xbox 360 is completely out of stock at most Japanese retailers,with stores unable to restock  immediately due to unexpected demand.

After years of poor sales, with the format selling an average of only2,000 or 3,000 units a month, demand has shot up following the releaseof Namco Bandai’s Tales Of Vesperia.

Generally regarded as Japan’s third most popular role-playing franchise (after Dragon Quest and Final Fantasy, but not including Pokemon), the new Tales game is exclusive to the Xbox 360.

The game sold 108,000 units in its first week and as a result became the fastest selling Xbox 360 title so far in Japan. At the same time, its release saw the Xbox 360’s hardware sales increase almost fivefold, to a total of 24,962 units – compared to 9,508 units for the PlayStation 3.

A message on the Japanese Xbox 360 website has apologized for the lack of stock, with blog site Kotaku translating the textas: "Currently, the Xbox 360 is sold out, and retailers are unable torestock their supply. This is a result of our own sales targets beingexceeded by the actual customer sales. We deeply apologize for thisinconvenience to our customers, retailers and business partners.

"Here at Microsoft, we are moving forward quickly with consoleproduction, and plan to ship the standard Xbox 360 model out thisSeptember. Furthermore, we will sequentially be shipping out the Eliteand the Arcade models. We ask that you please patiently wait until theconsole is shipped."