清純ヒーロー×ビッチ墜ち!!～悪の組織に調教される乙女の心の移ろいは…～

The magical heroine “Satsuki” is defeated in battle and captured. What awaits her is forced fellatio, brainwashing, and losing her virginity.

The next thing she knows, she loses her “purity of heart”...

[From official site]