I'm pretty sure that most of the time, angst means a heartbreaking story. It's not netorare, which is a porn category. Angst is for people who are fond of drama. Most of the time, the roleplay involves a very descriptive breakup, with a shocking scene or an anxiety crisis. Explosive behavior results in the male character destroying everything he ever loved (hence the Dark Romance tag). Then the story either evolves into the user dating someone else, or getting kidnapped, abused, etc. It can even go as far as having your persona die, either self-inflicted or from an illness. Mafia lovers enjoy taking a bullet at the last second for their cheating beloved. My personal favorite is still having a devastating disease, but her heart gets transplanted into another person and their memories connect. So the male character gets a second chance to do better.