Angel and devil are for the Slut and Lover Paths They are just for which path you want to go. All the scenes are like that, It´s a set of pictures. But i´m not sure how you´re not progressing with Anna´s hearts.. Would help if there was like, screenshots or something to go off of to see where you´re at. But you can also refer to this guide. Has EVERYTHING you need.
Starmaker Guide and FAQ