Ponytail to Shushu Sells Over Half a Million Copies on the Week of Its Release

http://stage48.net/forum/viewtopic.php?f=4&t=2275&start=816

Japanese site: http://www.oricon.co.jp/news/rankmusic/76755/

"Best first week numbers for a female group since Momusu's Renai Revolution 21 (515k) released approx. 9 years and 5 months ago. Best first week numbers for a female artist since Utada Hiraku's Can You Keep a Secret? (784k) approx. 9 years and 3 months ago." (Thanks to aakun of S48 [from the first link] for the translation)