When an artifact known as the "King's Seal" is 'borrowed' during transport from Soul Society, Tōshirō Hitsugaya is assigned to retrieve it. Hitsugaya goes missing after a battle with the thieves, leading Seireitei to suspect him of treachery. They order his immediate capture and execution. Unwilling to believe that he is capable of such a crime, Ichigo Kurosaki, Rukia Kuchiki, Rangiku Matsumoto, and Renji Abarai set out to find Hitsugaya and clear his name.

Meanwhile, Hitsugaya is still searching for the thieves, and stumbles upon a dark secret involving a shinigami long since dead, a man named Kusaka Sōjirō. He was a good friend and rival to Hitsugaya when they were young