According to the Media Create sales charts (via Gematsu), Watch Dogs sold 94,623 copies in Japan in its first week since launch. 63,595 of those copies were of the PlayStation 4 version, which was the second best selling game in Japan that week. The PlayStation 3 version came in at the No. 6 spot with 31,028 copies sold.
As you can see, the rest of the chart is dominated by Japanese games:
Watch Dogs is out on Xbox 360, Xbox One, PlayStation 3, PlayStation 4, and PC. While there has been talk of a sequel, if it ever happens it won't take nearly as long to develop, Ubisoft said in April.