The story how Amber betrayed MI6, how Pai and Hei ended up at the Syndicate, and the story of Heaven's war. Familiar faces everywhere, this story will tell you how Hei became a contractor. Based on Darkeer than BLACK and DTB: Shikkoku no Hana.

After the event that took place in the Hell's Gate four months prior to the start of this story, Hei remains on the run with an unconscious Yin. Meanwhile, Misaki Kirihara and the new Syndicate attempt to track him down.