Here's a breakdown of the key elements:
Setting:
* 2020, Tokyo: The story unfolds in a modern, fictionalized version of Tokyo, Japan.
* Heaven's Gate: This is a fictional area in the sky that has opened up, allowing Contractors to enter the human world.
* Special Zone: A district of Tokyo that is heavily guarded and where most Contractor activity takes place.
Characters and Themes:
* Contractors: These individuals are normal humans who have gained supernatural powers by making a pact with the "Heaven's Gate." Their abilities are often fueled by a "Dark Energy" that requires them to sacrifice something in return for their power.
* Hei: The protagonist of the series, a Contractor with the ability to control electricity. He is a mysterious figure working for a shadowy organization and is known for his ruthlessness and efficiency.
* Yin: A Chinese Contractor with the ability to manipulate shadows. She is often partnered with Hei on missions and acts as his "handler."
* The Organization: A clandestine group that operates in the shadows, manipulating events and using Contractors for their own ends.
* The Power of Choice: The show explores the ethical complexities of power and the choices individuals make when faced with extraordinary abilities.
* Humanity and Morality: The characters are constantly challenged to grapple with the consequences of their actions and the morality of their choices, especially as they navigate the dangerous world of Contractors.
* Mystery and Intrigue: The story features twists and turns, a complex conspiracy, and a constant sense of uncertainty about the true motivations of the characters and the nature of the "Heaven's Gate."
Overall, "Darker than Black" is a dark, suspenseful anime that blends action, science fiction, and a touch of supernatural elements to explore themes of power, choice, and the human condition in a world where extraordinary abilities come at a cost.