Following her arrest in the Human World, Rukia is brought back to Soul Society, where she is sentenced to death by the Central 46. Following this sentence, she is detained in the Senzaikyū. Her four Human friends, Ichigo, Uryū Ishida, Orihime Inoue, and Yasutora Sado set out on a bold rescue attempt, lead by Yoruichi Shihōin. They were later joined by Ganju Shiba and Hanatarō Yamada.
The attempt caused much chaos within the Seireitei, but most of the intruders were apprehended and detained. Yoruichi takes Ichigo to a secret location where she introduces a training program to help him become strong enough to save Rukia within three days, but during his second day, they learn Rukia's execution date has been moved to noon of the following day, August 6th.
On the morning of the execution, Rukia is taken by her executioners out of the Senzaikyū to the long walk to Sōkyoku Hill. While on the bridge, she, sensing the Reiryoku of Lieutenant Renji Abarai disappearing, realizes he was defeated by someone with enormous Reiryoku before seeing Captain Gin Ichimaru approaching her. As Gin talks to her, Rukia remembers how the captain always gave her an uneasy feeling whenever he was around her. When Gin tells her he thinks Renji is still alive, Rukia realizes he is correct.
When he says Renji will probably die for having tried to rescue her, Rukia, accusing him of lying, refuses to believe Renji would do such a thing. Asking if she is afraid of dying, Gin, offering to free her and her friends, allows Rukia a moment of renewed hope before crushing it by saying he was merely joking. Having shattered Rukia's resolve to go peacefully towards her end, Gin, walking away, smiles as he hears Rukia's anguished cry.
Countdown to the End
As she arrives at the execution site on Sōkyoku Hill, Rukia is placed on a platform underneath the gallows. Captain-Commander Genryūsai Shigekuni Yamamoto orders the beginning of the execution ceremony. Second Division captain, Suì-Fēng, tells her lieutenant, Marechiyo Ōmaeda, the attendance is very poor, for only the captains and lieutenants of the Second Division, Fourth Division, and Eighth Division have arrived.
Stating the absence of the injured captains of the Fifth Division, Eleventh Division, and Twelfth Division is to be expected, but none of the others have any excuse. Just then, she is taken aback a bit as she notices the arrival of Captain Byakuya Kuchiki, captain of the Sixth Division and Rukia's adoptive older brother. Rukia also realizes that Byakuya has arrived, and stunned, she stares at him for a long moment. Despite her eyes not leaving his face, Byakuya turns away without a even a glance in her direction.
When Yamamoto asks Rukia if she has any last words, Rukia states she only has one thing to say. She requests her friends be allowed to return safely to their homes in the Human World. When Yamamoto states her request will be granted by the following morning, Rukia thanks him, but 4th Division lieutenant, Isane Kotetsu, finds the deception cruel because none of the Ryoka will be allowed to live.
This prompts Captain Retsu Unohana to tell her it was in fact kindness of Yamamoto, which will allow Rukia to pass on in peace. Yamamoto gives the command to release the seal of the Sōkyoku. As the executioners begin the release sequence of the Sōkyoku, Rukia, noticing she has regained the resolve she lost after her encounter with Gin, wonders if it was Yamamoto's response to her request which soothed her spirit, or Byakuya's conduct when he arrived at the sight. Looking at her brother, she thanks him in her heart.
Rukia watches as three squares appear on the platform she is standing on, one directly in front of her and one on each side. As the squares begin to rise, revealing three cubic blocks which detach from the platform, Rukia's bonds are removed, and the two blocks on her sides climb to the height of her shoulders. As her hands are locked straight up to the sides of her body, the middle block stops at her heels, keeping them in place. As Rukia, held by the three blocks, is lifted to the top of the gallows, 8th Division Lieutenant Nanao Ise seems quite upset by this.
When her captain, Shunsui Kyōraku, asks her to cheer up or he will be saddened as well, Nanao, apologizing, says she did not mean to expose her emotions. Before the astonished eyes of the top officers of the Gotei 13, the huge pole of the Sōkyoku bursts into flames. All look on as the huge halberd transforms into a gigantic flaming bird. As it towers over the tall gallows, Yamamoto states the bird's name is Kikōō, the true form of the Sōkyoku's blade, and once it pierces one's body, the capital punishment is enforced.
Realizing she is not afraid of dying, Rukia is thankful for all the good she has had in her life: her childhood friends, her adoption by Byakuya, the guidance of Kaien Shiba and the Ryoka's rescue attempt. Thanking all these in her heart, she bids them farewell. As Kikōō flies towards her, the entire gallows is engulfed in its flames. Shutting her eyes while the flame overcome her, Rukia waits for her death.
However, when death does not come, she opens her eyes and is astonished by what she sees: Ichigo stands in the air, blocking the bird's attack with his Zanpakutō. To Ichigo's surprise, Rukia tells him he will not be able to defeat Byakuya, and will surely die this time. Having already resigned herself to her fate, she urges him to go away.
Struggling to understand how Ichigo could possibly stop the Sōkyoku, whose power is equivalent to one million Zanpakutō, Suì-Fēng wonders who he is. When Shunsui asks his lieutenant if Ichigo is one of the Ryoka, she, confirming it, says he fits the description. As Shunsui states the one who arrived on time is an outsider, Kikōō calls out in anger. Alarmed, Ichigo, turning to it, sees it has backed up for another attack.
Pleased to see this, Ichigo challenges Kikōō to come again. As Rukia warns him he will never survive a second attack, Ichigo, ignoring her, prepares for the attack, but to everyone's surprise, Kikōō's neck is bound by a rope, which is held by 13th Division captain, Jūshirō Ukitake, who is accompanied by his two 3rd Seats, Sentarō Kotsubaki and Kiyone Kotetsu.
Reaching the ground, the other end of the rope is grabbed by Shunsui, accompanied by Nanao. When Shunsui berates his friend for his late arrival, Ukitake states breaking the seal took longer than expected, but now everything is prepared. As he presents a large shield connected to the rope holding the bird, Suì-Fēng, recognizing it as the Shihōin Shield, realizes the captains are trying to destroy the Sōkyoku.
Though she orders Ōmaeda to stop them, there is not much he can do against two captains. As the captains release a surge of energy from the shield up the rope, the surge reaches the bird, which disappears, and the broken pole falls to the ground while the blade shatters into thousands of pieces.
Landing on the top of the gallows, Ichigo tells Rukia he intends to destroy it. When she tries to stop him, he, telling her to keep quiet and watch, stabs the top beam and channels his Reiryoku into the gallows, destroying them. Saying he is fed up with hearing Rukia tell him to leave her and run away, Ichigo, holding her under his arm, reminds her this is the second time he has come to her rescue. Stating he is an idiot, Rukia tells him she will not thank him for this.
Down on the ground, everyone wonders who Ichigo is to possess such power, while Byakuya looks at him with disdain. When Rukia asks Ichigo what he intends to do now, Ichigo says he intends to run. Rukia declares that they could not possibly outrun every single one of the captains in the immediate facility but Ichigo rebuffs her argument. He insists that all their friends will need help including Yasutora Sado, Orihime Inoue, Uryū Ishida, Hanatarō Yamada, Ganju Shiba and anyone else who helped them.
As he asserts that they will all be rescued and taken back to the Human World, Rukia is filled with strength by Ichigo's words and the look in his eyes. Hearing a short scuffle on the ground, they see Renji, who has taken out the executioners. Calling Renji's name, Ichigo lifts Rukia through the air and, despite the objections of both Rukia and Renji, hurls Rukia straight to Renji, who manages to catch her before being thrown back by the impact.
Recovering, both Rukia and Renji protest Ichigo's recklessness. Ignoring them, Ichigo tells Renji to take Rukia and run away, and to not let go of Rukia even if he should die. As Renji runs away, the other lieutenants, shocked by the betrayal of one of their peers, stare after him in confusion until Suì-Fēng shakes them by ordering all of them after Renji.
As Ōmaeda runs after him, Isane, and First Division lieutenant, Chōjirō Sasakibe receive their respective captains' permission before going. Running, the three are stopped by Ichigo, who, lodging his sword into the ground, blocks their path. As the three lieutenants release their Shikai, the unarmed Ichigo, defeating them all in seconds, blocks an oncoming attack by Byakuya.
The attendees of the execution break into three separate battles. Ichigo fights Byakuya, Yamamoto takes on Shunsui and Ukitake, and Yoruichi Shihōin steps in to fight Suì-Fēng. Renji keeps running with Rukia until he encounters an interference which will change the face of Soul Society forever.