Atlus exec Tim Pivnicny didn't give exact figures, but confirmed that the game had broken the record, saying, "Catherine has exceeded our highest expectations."
"It released last week to tremendous critical acclaim and fan response," Pivnicny continued, "bolstered by the release of a demo a couple weeks prior, and continues to generate discussion among fans for its mature themes, engrossing subject matter, and frantic, challenging gameplay.
"It is fitting, then, that Catherine can boast the largest launch in the 20-year history of Atlus, and continues to see strong sales at retail."
Catherine has been a big hit with Westerners as a strange melding of dating sim and incredibly difficult puzzle game. The game has garnered a Metacritic rating in the mid-80's for Xbox 360 and PlayStation 3.