Shimazu Toyohisa is a real-life samurai who fought in the pivotal Battle of Sekigahara. In his dying moments, Shimazu is transported to a world of magic with other famous warriors throughout history. These warriors are forced to fight each other in an endless battle.

The show revolves around Ichigo Kurosaki, a good-hearted 15-year-old high school student who carries the undesired ability to see spirits. Others in his family (two sisters and his father) carry this ability to some extent as well. One evening, he encounters Rukia Kuchiki; a Shinigami, or Death God. It is her job to usher lost spirits to Soul Society, and to also eliminate those which cross over from the Hollow World.

Two years have passed since the final battle with Sephiroth. Though Midgar, city of mako, city of prosperity, has been reduced to ruins, its people slowly but steadily walk the road to reconstruction. However, a mysterious illness called Geostigma torments them. With no cure in sight, it brings death to the afflicted, one after another, robbing the people of their fledgling hope.