It sold 49,576 copies!
With the sole exception of Nanchatte Renai (54,973), this is Morning Musume's highest selling first week in four years. And it's their 3rd highest first week in six years, only beat out by the above mentioned Nanchatte Renai as well as Kanashimi Twilight (53,551).
I think we've already accomplished sending away Aichan in style and we still have a few more weeks to add to this single's sales before it drops out the charts. Now's not too late to buy it!
Aichan version: http://www.cdjapan.co.jp/detailview.html?KEY=EPCE-5807
Regular edition: http://www.cdjapan.co.jp/detailview.html?KEY=EPCE-5806