To those 'fortunate' enough to have an Xbox 360 in Japan will have to resort to buying a PS3 or importing an Xbox 360 copy of the game outside of Japan. An official message on Kojima Pro's website announced that the Japanese port of Metal Gear Rising: Revengeance has been cancelled.
The reason for the cancellation was vague with the official comment being, "due to various circumstances".
The site apologised to gamers looking forward to playing the Japanese version on the X360, as well as to partners who might be affected by the decision.
A poor Japanese/English Translation Japanese Link
This time, we plan to release on February 21, 2013
Regarding software for Xbox360 Version of "Metal Gear Rising re vengeance",
due to various reasons, the launch of the Japanese version be made only PlayStation ® 3 indeed without permission I was going to get.
Customers We have been looking forward to the launch in the Xbox360, to everyone of the persons concerned, and sincerely apologize for the inconvenience that will be multiplied. Look forward to pardon humbly for your understanding, thank you.
The post didn't mention anything about affecting the International version so it's probably safe to assume that the Xbox 360 version in other territories is good to go.