Xbox has historically struggled in Japan, and apparently its latest interation is no exception.
Reports from Japanese gaming publication Famitsu indicate that the system only sold 23,562 units from its release on September 4th through September 7th. That's a pretty dismal number, especially considering that the Xbox 360 sold 62,135 units nearly ten years ago, and the original Xbox managed to clear 123,929 units during its launch.
Those numbers are small compared to what the both Wii U and PlayStation 4 sold in Japan during their launch. Nintendo's system sold 308,000 during its initial release in 2012, while the PlayStation 4 did reasonably well with 322,000 units sold.