Akuyaku Cinderella Manga Summary
From Wildflower Scans:
Tachibana Ayaka is roped into playing the role of Lady Betray, a flashy female villain, in a local hero show, when all she wanted was a free gift for her adorable little brother. Her co-star, Kazama Shun, plays Bardian, the hero and Guardian of Dreams, but he is only in it for the money! How will the two of them get along when they're so different?