Ichigo Kurosaki is a teenager who is different from many humans in that he has the ability to see spirits. His life is changed drastically with the sudden appearance of a Soul Reaper – one who governs the flow of souls between the human world and the afterlife – named Rukia Kuchiki, who arrives in search of a “hollow”, an evil spirit that was originally a human soul. After Rukia is severely wounded while trying to defeat the hollow, she attempts to transfer half of her reiatsu to Ichigo in order to let him face the hollow on equal footing. Ichigo unintentionally absorbs almost all of her energy, transforming him into a Soul Reaper and allowing him to defeat the hollow with ease. With her powers diminished, Rukia is left stranded in the human world until she recovers her strength. In the meantime, Ichigo must take over Rukia’s role as a Soul Reaper, battling hollows and guiding lost souls to the afterlife realm known as Soul Society.
As time passes and Rukia has yet to return to Soul Society, her Soul Reaper superiors find out about her whereabouts and actions, sentencing her to death because she had performed an illegal act by giving away her powers; a detachment is sent to retrieve her. Although he is unable to stop Rukia’s departure from the real world, Ichigo resolves to rescue her, and, with the aid of several of his classmates who also possess spiritual abilities, Yoruichi Shihoin, and ex-Soul Reaper Captain Kisuke Urahara, sets off for Soul Society. Once there, Ichigo and company battle against the elites of the Soul Reaper military and strive to reach Rukia before her execution.
It is revealed that both Rukia’s execution and Ichigo’s rescue attempt were manipulated by Sosuke Aizen, a high ranking Soul Reaper previously believed to have been murdered, as part of a far-reaching plot to take control of Soul Society. Aizen betrays his fellow Soul Reapers and allies himself with the strongest of the hollows, the Espadas – the elite few of the arrancar. Aizen thus becomes the main antagonist of the series and the Soul Reapers form an alliance with Ichigo. At this point, Bleach chronicles the war between the Soul Reapers and Aizen, who intends to garner souls from Ichigo’s hometown in order to create the King’s Key, a device that could open a portal to the location of the king of Soul Society.
The plotline has yet to be resolved; according to Tite Kubo, the ending of the series is not yet planned out or written