Season 1 Chapter 1 - 12 End
In Tokyo, an impenetrable field known as "Hell's Gate" appeared ten years ago. At the same time, psychics who wield paranormal powers at the cost of their conscience also emerged. Hei is one of the most powerful of these psychic agents, and along with his blind associate, Yin, works for one of the many rival agencies vying to unlock the mysteries of Hell's Gate.
Season 2 Chapter 1 - 25 End
Two years have passed since Hei and Yin escaped the Syndicate after the events of the first season. Making their way to Russia, Hei encounters a young girl named Suou Pavlichenko, whose family is gradually pulled into the war between contractors and various intelligence factions. Meanwhile, Misaki Kirihara has quit her position in Foreign Affairs to begin her own investigations into Hei, the Contractors and the Syndicate.