Australian Classification has rated something called “Catherine Classic.”
The game is listed as developed by Atlus and published by Koch Media, which distributes Atlus titles in Europe. The applicant for the rating is Atlus parent company Sega.
While Catherine: Full Body, a new version of the original Catherine that adds a third heroine to the story plus various other features, is planned for release on PlayStation 4 and PS Vita on February 14, 2019 in Japan, Atlus has not announced plans to bring the original Catherine to modern platforms.
Read more about Catherine: Full Body here, here, here, and here.