I Harvest Emotions in the Human World

In a highly developed near-future city, there exists a hidden financial class - "emotional financiers". They don't trade stock futures, they trade humanity's most primitive and valuable asset: emotions. Joy, sadness, fear, anger... These emotions can be refined to become luxury fuel, a source of artistic creation, and even a secret elixir for extending life. The protagonist is an "emotional reaper" in this class.