As Sōsuke Aizen strolls through Karakura Town, Ichigo Kurosaki undergoes furious training in order to master the one technique that could bring an end to the conflict. But when the battle is finally over, how will Ichigo's world have changed…?
Gin reveals his true intentions to Aizen, by impaling him through the chest.
After Gin Ichimaru announces that he has returned, Aizen asks what happened to Lieutenant Rangiku Matsumoto. Gin says that he has killed her and Aizen notes that her Reiatsu has disappeared. Aizen expresses his surprise, as he had thought that Gin had more emotions towards her. Gin replies that he has no such thing and that he had previously told Aizen that he is a snake that eats anything that looks tasty.
Meanwhile, Keigo Asano urges Tatsuki Arisawa and the others to stop watching and run away. As Aizen says he is bored of catching mice, Gin asks what they will do after killing them. Aizen states that they will hang their corpses in visible locations outside the town and then create the Ōken. Gin places his hand on Aizen's Zanpakutō and says that he shall kill them. Gin then stabs Aizen in the chest, revealing that the only way to escape its ability is to touch the blade before its complete hypnosis is activated, wondering how many decades it took for him to learn that fact. Gin states that despite none of them knowing this, the Gotei 13 still tried to kill him. He says that he is the only one who can kill Aizen.
Aizen reveals that he knew of his intentions, which is why he brought him to Karakura Town and asks Gin if he thought it would be that easy to kill him. Gin informs Aizen that he left a chip of Kamishini no Yari inside his heart and then tells Aizen that he lied about his Bankai's abilities, as it turns to dust one moment while extending and on the interior of the blades is a deadly poison, capable of breaking down cells. He then explains while attacking him that dust was left in his heart with the poison, and no matter what he does, he will die with a hole in his chest, as he has long desired.
Just as Gin takes the Hōgyoku, Aizen goes through yet another transformation and counterattacks.
Gin recalls his childhood before he became a Shinigami. As Gin is gathering firewood, he spots Aizen in a clearing through a bush. Three other Shinigami are in the clearing, one of them holding an object up to Aizen. Aizen then takes the object, the Hōgyoku, and places it in a glass container as Gin watches on.
Back in the present, Gin slowly reaches into the large hole in Aizen's body and grabs the Hōgyoku just in time before Aizen slaps him away. Aizen than falls on the ground and utters Gin's name. Suddenly, Aizen screams out in pure rage as an energy wave overtakes him. Gin looks at the Hōgyoku in his injured right arm. Gin than closes his eyes and thinks to himself that now that he has the Hōgyoku, everything is over. Just than, a large pillar of light emits from where Aizen was standing. Aizen emerges from the pillar with the hole from Kamishini no Yari no longer present, and also in a new angelic form. Giving a menacing smile, Aizen announces his victory to Gin, saying that the Hōgyoku is his, even now that it has been removed from his body. The Hōgyoku begins to glow brightly which greatly shocks Gin. Aizen almost immediately appears next to his former subordinate.
Gin continues to remember watching Aizen hand the Hōgyoku back to the Shinigami who gave it to him. Gin goes on to recall the day he found Rangiku and remembers that the three Shinigami with Aizen were nearby. He thinks to himself that Aizen is the leader. Gin then opens his eyes, thinking that Aizen is the one he must do something about. However, before Gin can finish his thoughts, in the present, Aizen cuts Gin deeply with a single swipe from his sword.
Rangiku remembers a snowy night from her childhood as she starts to regain consciousness, on the rooftop. She comes to realize that Gin cast the Kidō spell Hakufuku on her to knock her unconscious. Down below, Gin has been slashed by Aizen across the chest. In Gin’s hand the Hōgyoku disintegrates and then rebuilds itself to take on the shape of a cross similar to the one in Aizen's chest. As he reaches for it, Aizen reflects on how he arrived at the solution that was the Hōgyoku even before Kisuke Urahara, but it was a failure. Aizen goes on to remember how he carved out the souls of hundreds of Shinigami and residents of Rukongai with Shinigami potential in an attempt to complete the Hōgyoku, but how the Hōgyoku was not satisfied. In addition, Urahara's research notes showed that Urahara's Hōgyoku was also incomplete. As a result Aizen decided to take Urahara's Hōgyoku to give it to his Hōgyoku.
He grabs Gin's wrist before he can take the Hōgyoku and effortlessly rips off his arm and stabs him through the chest. Looking down at Gin, Aizen says that fear is necessary for evolution of the Hōgyoku. He then thanks Gin for helping him get this far, and that he has now become something much more powerful than a Shinigami and Hollow, and that Gin's fear could have been eliminated at any moment, but he needed it to help the Hōgyoku evolve. Aizen thanks Gin for his efforts and throws him through a building. Ichigo's friends, still trying to escape, stop as the building near them collapses. As they see Aizen walk into view, Keigo wonders what he is, as Aizen's Reiatsu paralyzes them as he approaches Gin.
On the brink of death, Gin recalls the memory of the snowy night Rangiku was thinking of earlier. He remembers how Rangiku ran out to him in the snow asking him why he has Shinigami clothes and where he got them. Gin wrapped the shihakushō around himself and replies that he wants to become a Shinigami and change things for her, change things so that Rangiku wouldn't have to cry any more. He is pulled away from the memory when he hears Rangiku scream his name as she jumps off the rooftop to him below. As he sees her he thinks how it didn't work and how in the end he couldn't get back what was taken from Rangiku. He thinks how fortunate it was that he apologized in advance. As she realizes that he is dying Rangiku gathers Gin in her arms and cries. From behind, Aizen closes in on them. Rangiku continues to grieve, not noticing Aizen. Just before he can harm her, Ichigo arrives with his unconscious father slung on his shoulder and looking different from before with a chain wrapped around his arm.
As Aizen looks down mercilessly at a weeping Rangiku and near-death Gin, Ichigo appears to everyone's surprise. Tatsuki and Keigo notice that he looks different: his hair seems longer and he looks a bit taller. Also, his right arm seems to have a black glove on it, that mostly covers his hand and forearm. Also, Tensa Zangetsu has changed as its guard has become more pronounced and seemingly messy looking, almost taped together. Its chain has also increased in length to encompass the whole of Ichigo's right arm, which also has the sleeve of his shihakushō removed.
Ichigo promptly thanks his unconscious father (now sporting a beard), and looks into the distance, closes his eyes and remarks that his sisters are all right, sensing their Reiatsu. Ichigo then takes notice of all his friends, although he trips up on Zennosuke's name, calling him "Imoyama-san", leading to a humorous outburst. He calmly tells them to stay there and he will deal with Aizen.
Tatsuki then comments to herself that she can't sense any of Ichigo's Reiatsu, whereas Aizen's is overwhelming. Aizen seems puzzled too, as he asks if he really is Ichigo, to which Ichigo asks what he means. Aizen then remarks that he is disheartened, because he cannot sense any Reiatsu from him. He then goes on to say that he gave Ichigo one last chance to evolve and face him, but he failed. Ichigo calmly ignores him and looks at a crying Rangiku and a half-dead Gin. Gin remembers Ichigo's many faces of fear in his eyes, but looking at them now calls them "strong". He silently resolves that Ichigo will finish what he could not and defeat Aizen.
Aizen then remarks how unfortunate Ichigo's lack of evolution is, but is interrupted by Ichigo who tells Aizen that he wishes to fight elsewhere. Aizen states that it doesn't matter, because only a being that can actually fight him should make that proposal. He sneers and goes on to say that Ichigo "couldn't possibly do any damage to-". Ichigo suddenly grabs Aizen's face and forcibly pushes him over a few miles and throws him into the ground, all with minimal effort. Aizen grips his visibly bruised face in disbelief that he was pushed and thrown by brute force alone. Ichigo then tells Aizen to get ready and that he will "end this in a single instant".
Repeating Ichigo's words "Finish this in an instant", Aizen claims to understand Ichigo's "lack of Reiatsu", that he hasn't "parted" with it, but instead "thrown it away." Although he does not know how, he postulates that Ichigo converted all his Reiatsu into physical power for his spiritual body; be it arm strength, leg strength, grip strength, throw strength, or running speed, all his physical abilities have received rapid growth in exchange for discarding his Reiatsu, as he has given up trying to compete with Aizen's. Aizen is undaunted, however, advising Ichigo to forsake all hope, that despite his new physical prowess, he will still be unable to reach him. He then warps behind Ichigo in an attempt to strike him. The two clash, and a mountain in the distance is instantly obliterated. Aizen comments on his ability to shape the earth with a single swing of his sword, that even he didn't expect his power to grow that much, and thanks Ichigo, for now he can test his power transcending Hollow and Shinigami to his heart's content. After another parry, Aizen comments on the similarity of their Zanpakutō's agglutination with their arms as an evolutionary discovery, that perhaps that is the proper form they should take. However, he says he understands the dimensions of their evolutions are different, and that if he wished it, he could destroy Ichigo's in a single blow, and prepares a back-swing, only for Ichigo to stop it barehanded as the earth around them shatters. Aizen is stunned; he could understand if Ichigo was to dodge it, even if Ichigo shouldn't be fast enough to do so, but for Ichigo to stop his strike is simply ridiculous to him. Ichigo asks what Aizen is so surprised by: Is it really that hard to believe he could stop Aizen's sword? Is he scared of what is before his eyes, of something happening that he cannot understand? Aizen pulls back, telling Ichigo not to speak so triumphantly, that he managed to momentarily exceed his own physical strength and nothing more. Aizen decides to unleash a full incantation of Hadō #90 Kurohitsugi, so as to prevent any further miracles by crushing him to atoms. Aizen lauds over his perfect casting with his power transcending Hollow and Shinigami, to create a torrent of gravity capable of warping space time, such that a being like Ichigo cannot even begin to comprehend. Ichigo allows the spell to surround him only to shatter it with the swing of his arm. As it crumbles, he notes that Aizen didn't notice, that he is stronger than him right now, and that the mountain was obliterated not by Aizen's sword, but by his, before rushing in to strike.
Aizen transforms again, but an unfazed Ichigo prepares to release the Final Getsuga Tenshō.
Aizen warps away, while shedding blood from his wound, onto a distant hill. Ichigo notices that he was the one who always distanced himself from Aizen, but now it is Aizen who is doing the running away. So Ichigo asks why Aizen has distanced himself from him. As Aizen's wound heals, he tells Ichigo to "abandon his arrogance", and then Aizen transforms again. He then realizes that the Hōgyoku will not allow him to be defeated by a "mere human". He then attacks Ichigo and burns his left arm. Aizen then says that Ichigo's arm won't be any use to him anymore. He then tackles Ichigo and grabs him by the throat and holds him there in midair, and creates a halo-like attack around him. Aizen says that Ichigo has lost his power and is now a mere shadow of his former self. Aizen then says that Ichigo is finished, to which Ichigo responds, "Finished? Is that all you've got?" He then slashes through Aizen's attack saying that they should put an end to this and that he's sick of Aizen's logic. Then Ichigo prepares to release the Final Getsuga Tenshō.
Ichigo flashes back to his fight against the combined form of Ichigo's inner Hollow and Tensa Zangetsu as he finally unleashes the Final Getsuga Tenshō.
As Ichigo prepares to use the Final Getsuga Tenshō, Aizen watches in shock and asks what that form is. Ichigo flashes back to his battle against the combined form of Tensa Zangetsu and Ichigo's inner Hollow. Tensa Zangetsu is overpowering Ichigo enough to send him flying into a building. Ichigo gets up, prompting Tensa Zangetsu to remark that Ichigo is still not giving up. Ichigo replies, saying that he will not give up until Tensa Zangetsu teaches him the Final Getsuga Tenshō. Tensa Zangetsu, however, says he does not intend to and rushes at Ichigo. Ichigo considers Tensa Zangetsu's actions. If he had wanted to defeat Ichigo, he could have easily done so by now and if he did not want to teach Ichigo the technique, why not go off and hide somewhere? Ichigo questions why nothing but sadness is spilling out from his blade. The two continue their fight and as Tensa Zangetsu charges at Ichigo, Ichigo discards his blade and allows his opponent to impale him. Ichigo tells Tensa Zangetsu that it does not hurt. Ichigo notices that his opponent is crying and asks why. Tensa Zangetsu responds that what he wanted to protect was Ichigo. Ichigo wonders what this means. Tensa Zangetsu tells Ichigo that the answer will come along with the essentials of the technique and gives him a warning. Ichigo is now back in battle with Aizen and tells him that the Final Getsuga Tenshō is to become Getsuga. Ichigo's form is now radically different with long black hair and bandages wrapping around his body. Ichigo says that if he uses the technique, he will lose all his Shinigami powers, hence why it is called Final. Aizen notes to himself that he still cannot feel anything. He is shocked to figure out that Ichigo is in a higher place than him. Aizen screams that it is impossible and charges towards Ichigo. Ichigo uses a new technique, Mugetsu, as the battlefield is swallowed by a black light.
Aizen survives Ichigo's Mugetsu, but falls prey to Kisuke Urahara's hidden seal.
Ichigo recalls what his Inner Hollow/Tensa Zangetsu said if he uses the Final Getsuga Tenshō. He remembers them bidding him farewell as he activates Mugetsu. Mugetsu completely envelopes Aizen in black light and literally cuts the land they were fighting on in half, leaving a massive crater miles wide. Getsuga/Ichigo lands and his cowl begins to break, revealing Ichigo's face, and the realization that he is indeed losing his Shinigami powers. A nearly bisected Aizen falls not 5 meters from him, and as Getsuga/Ichigo looks at him, the massive gash caused by Mugetsu begins to regenerate. Getsuga/Ichigo quickly teleports to a very angry, heavily injured, but very much alive Aizen and begins to attack again.
But then, the black leaves Ichigo's hair and it returns to its normal length and color. A now-powerless Ichigo collapses on the ground, as Aizen rises in triumph to show Ichigo his disintegrating Zanpakutō, indicating the Hōgyoku has decided he [Aizen] doesn't need a Zanpakutō to become stronger. He exclaims that Ichigo has lost and is finished when a beam of light comes out of his chest.
Aizen, surprised and nervous, wonders how a Kidō was activated as more lights spring out of his chest and abdomen. Kisuke Urahara appears and calmly says that "it finally activated". Aizen asks when he did this, and Urahara replies that it was right before Aizen's complete transformation, at his most vulnerable. Urahara goes on to say that he knew it would be virtually impossible to kill him [Aizen] when he was fused with the Hōgyoku, so he created that seal to seal him. Aizen nods his understanding, but yells the futility of it as he is reaching a new stage of evolution and will not be stopped by a lowly Kidō. Urahara looks on impassively as Aizen's Hōgyoku-enhanced form begins to flake off of him, much to Aizen's horror.
Urahara explains that the seal he used was to activate at this moment: the moment when Aizen was weakening. He says simply: "The Hōgyoku no longer sees you as its master". Aizen, at first in disbelief, then acceptance, furiously yells at Urahara and tells him that he despises him. Aizen hates that a man of Kisuke's intellect sits idly by and is controlled by "that thing!" Urahara clarifies that Aizen is talking about the Soul King, and comments that Aizen saw "it", the Soul King. Urahara then says that the Soul King is the lynchpin holding Soul Society together and if said lynchpin was lost, Soul Society will split and crumble. A screaming Aizen counters with that being the logic of a loser and that he, a "winner", must think of not how the world is, but how it should be.
As Ichigo looks away, Aizen is sealed into a large, spiked monument.
In the wake of Aizen's defeat, the battle ridden Gotei 13 gathers itself.
Captain Mayuri Kurotsuchi is seen preparing to bring back the real Karakura Town to the Human World. A Shinigami runs up to him and says that a material transfer without the aid of a Senkaimon would be dangerous since there are still Shinigami there. Mayuri says that he will give them ten seconds to activate the Senkaimon, and the Shinigami yells to everyone, "Hurry! We're gonna die!!!" Mayuri then states that this generousness makes him want to puke. Captain Retsu Unohana has healed all of the Visored, but she cannot predict if Hiyori Sarugaki will give up living or not. Shinji Hirako then says that he owes her one. Unohana calmly tells him that she is just merely healing her allies, to which Shinji says that they're not allies, but Shinji thanks her again.
Then, Captains Byakuya Kuchiki and Kenpachi Zaraki return from their fight with Yammy Llargo in Hueco Mundo. Their division members welcome them back, and some Shinigami request medical aid for the two captains. The 11th Division asks how the fight was this time, and Kenpachi says that it was too boring. In Hueco Mundo, Yammy is laying dying with his head smashed into a stone building. The Hollow dog from a long time ago returns, and Yammy looks at it. He asks, "Why'd you come back, you stupid dog..." With that, Yammy Llargo dies.
Back in Soul Society, where Ichigo's fight took place, Ichigo is gazing up into the sky, Urahara calls him, and Ichigo asks where everyone is. Urahara says that they all went home, and that they wanted to talk, but it seemed like an equally difficult task. Ichigo then asks if their memories were replaced, and Urahara answers with a no. Ichigo says good, and that he wants to explain to them with his own mouth. Urahara announces that Aizen's seal was transported to the Seireitei, where the Central 46 is deciding Aizen's disposal. Ichigo says "oh", and then looks down. Urahara asks why he is making such a sad face, and Ichigo looks up in surprise. He says that he's wondering why himself. Urahara tells him that he saved Karakura Town by sealing Aizen, and risking his own life, and that he shouldn't make that face. Ichigo sits down on a rock and doesn't answer. Ichigo then asks Urahara if Aizen really was rejected by the Hōgyoku. His dad had told him about the Hōgyoku and that its ability was to take in the "hearts" around them and materialize them. But if that's so, then Aizen might have wished losing that power. He then says that he had acquired the right amount of power to defeat him, and he had finally touched it in battle. In Aizen's blade was only "solitude". Ichigo thinks that Aizen was searching for a person with the same viewpoint of the world as he had. Aizen just kept wishing that he was "just a Shinigami."
Then, Orihime Inoue, Uryū Ishida, Rukia Kuchiki, Yasutora Sado, and Lieutenant Renji Abarai all appear. Ichigo looks at them in surprise, and asks them if they're supposed to be standing already. Rukia tries to answer, but Orihime interjects, saying that she knew it was Ichigo, but his hair was all grown out, so she wasn't sure. Ichigo replies that she's making such a weird face and his hair is just messy. Then, all of a sudden, Ichigo drops to his knees and collapses. Everyone stares in shock, and then they all run forward to help him, as Ichigo screams in agony.
Aizen is sentenced to his fate by the Central 46, while Ichigo finally awakens and copes with his loss of Shinigami powers.
When the Central 46 sentences Aizen to 18,800 years in Muken, the eighth and lowest level of the underground prison, Aizen scoffs at the idea of them passing judgment on him. Aizen is warned not to be so "high and mighty" just because he is immortal and his eyes and mouth are bound. Aizen's sentence is increased to 20,000 years.
In the First Division barracks, Captain-Commander Genryūsai Shigekuni Yamamoto scolds Captains Kenpachi, Byakuya, and Shunsui for losing their captain's haori and acting as if it was not important. Byakuya offers to replace the "cheap" haori, but Yamamoto replies that he is not worried about that and that they are not cheap. He tells them that battles are not just about winning and demands to know what they think a captain's haori is, but is angered by their response that they are dead weight, cheap and fashion statements. Outside the barracks, Captain Jūshirō Ukitake comments to Co-3rd Seats Sentarō Kotsubaki and Kiyone Kotetsu that ten days after the battle, Yamamoto has recovered his strength despite losing his arm, noting that there is nobody in Soul Society who could replace him.
In the Twelfth Division compound, a member of the Division informs Akon that Rangiku is there to visit Lieutenant Momo Hinamori, who is undergoing organ restoration at the Division. Akon tells him that Mayuri is in Hueco Mundo and goes to explain the situation to Rangiku. However, she is no longer there.
Meanwhile, Captain Tōshirō Hitsugaya is training with his Bankai in a cave. He notes that at this rate he will never be able to protect Hinamori and that he needs to be better able to control his Bankai and his Shikai. In the shadows nearby, Rangiku thinks to herself that everyone is moving on. She notes that Lieutenants Renji and Shūhei Hisagi were not in their barracks and most likely were training. She thinks about Gin, noting that she hated the way that whenever he disappeared, he did not leave anything for her to remember him by behind. But she is sure that Gin knew if he did leave anything behind she probably would not be able to move on, and states that she loved that part of him.
In the Kurosaki Clinic, Ichigo awakens a month after collapsing. Rukia explains what Urahara told her about the loss of Ichigo's Shinigami powers, as Ichigo says that he will have to give up being a Substitute Shinigami. Rukia tells him that his remaining power will also disappear. Rukia is surprised at Ichigo's easy acceptance of it. They go outside, where Ichigo notes that he cannot sense any spirits and that Rukia's presence is fading. Rukia comments that she will still be able to see him, which does not reassure Ichigo, who asks her to tell everyone that he said hi. As they say goodbye, Rukia fades from Ichigo's sight.