Bleach - Specials (2004)

On the anniversary of his mother's death, Kurosaki Ichigo travels to his mother's grave. When Rukia arrives, Ichigo leaves to speak with her; but what she has to say upsets him. His sisters have a much bigger problem, however: they're being attacked by a particulary vicious Hollow with a few tricks up his sleeve. But this isn't any ordinary Hollow! Could it have something to do with the death of Ichigo's mother? Ichigo must discover the truth and fight the Hollow on his own to protect his pride.

A brief intro of the 13 Squad Captains.

A Shinigami named Baishin who was sealed by Soul Society long ago is set free on Earth. On a fateful day Ichigo encounters him and has roughly half of his reiatsu drained. Its now up to Ichigo and Soul Society to finally put a stop to Baishin and his destruction.