I am Mel Pure! Pure Blue! Yasaka Nagi SPSF-81

To protect humanity from the ravages of the demon race, the evil demons, the pure angel/Amamiya Ren fights relentlessly. Today, she rescues a man attacked by the evil demons. However, the man becomes a hostage, subjecting Ren to torture. Even worse, the evil demons threaten the man to abuse Ren's body. After seizing an opportunity to fight back and save the man, she is almost able to defeat all the evil demons! But what stands in her way is the man she rescued. This man, who has never been with a woman before, has sided with the evil demons because he wants to enjoy Ren's body more. As a result, not only is her brooch destroyed and her energy drained, but Ren also begins her descent into hell. [BAD END]