Khalid Alahmadi, 23, of Cardiff, was arrested following allegations of assault in Gorsedd Gardens on Thursday.
The court heard Mr Alahmadi was a student at the University of South Wales in Treforest.
He was remanded in custody and will appear in Cardiff Crown Court on 12 October.
A man has appeared in Cardiff Magistrates' Court charged with the attempted rape of a 19-year-old student in the city centre.