Bleach - Season 1 Episode 251 Dark History! The Worst Shinigami Is Born
Overview: 6th Division Captain Ginrei Kuchiki and Captain-Commander Genryūsai Shigekuni Yamamoto are forced to seal Kōga Kuchiki away. In the present, 6th Division Captain Byakuya Kuchiki stops Kōga from killing Muramasa.