From J-Novel Club:
"Hi, I’m Hiiragi Utena. I’m a normal magical-girl-loving middle school girl or at least I was, but then some talking mascot showed up out of the blue and cast a spell on me. Now’s my chance to join my beloved magical girls as a villain. Hang on, something’s wrong with my outfit. This can’t be happening! Watch this shy magical-girl fan transform into a sadistic dominatrix! When good and evil collide, who will be the one to submit?"

Original Webcomic
Official English Translation