BLEACH: The DiamondDust Rebellion - Mou Hitotsu no Hyourinmaru

A valuable artifact known as "King's Seal" ("Ouin") is stolen by a mysterious group of people during transport in the Soul Society. Toshiro Hitsugaya, the 10th Division Captain of Gotei 13, is assigned to transport the seal, fights the leader of the group, and shortly after, goes missing. After the