Uryū Ishida vs. Jirōbō Ikkanzaka is a fight taking place during the Ryoka Invasion between Quincy Uryū Ishida and 7th Division 4th Seat Jirōbō Ikkanzaka, serving as Uryū's opportunity to display the results of his training.
To break into the Seireitei and rescue Rukia Kuchiki, the Ryoka infuse the Reishūkaku with their combined Reiryoku in order to create a cannonball that can penetrate the Shakonmaku; however, Ichigo Kurosaki is unable to lower his Reiryoku output to match that of his friends and distracts Ganju Shiba while the latter is reciting the second incantation for Kagizaki, the spell guiding their cannonball, at a crucial moment, resulting in the unstable cannonball exploding, which sends the Ryoka flying in four different directions across the Seireitei.
Having been paired up with Uryū Ishida by Yasutora Sado for their safety, Orihime Inoue uses Santen Kesshun to cushion their impact as they hurtle toward the ground. Soon afterward, upon envisioning Ichigo standing over her, Orihime Inoue bolts awake and bashfully declares that they are going to engage in close-quarters combat, but finds herself in pain when she strains her bandaged right arm in the process. Asking Orihime if she is alright, Uryū apologizes for not being Ichigo and explains that they got lucky by landing in an area that seems to have no one around.
As she agrees that this is lucky, Orihime clutches her bandaged arm when it stings again, prompting Uryū to instruct her to be careful because she was injured in the crash and he could only bandage her wound because he did not bring any painkillers. Orihime thanks Uryū and expresses surprise at him carrying bandages around, and when Uryū apologizes for her getting hurt because it would not have happened if she did not need to use her powers to protect him, Orihime asserts that she would have gotten hurt anyway due to how clumsy she is. After getting to her feet, Orihime points out that no one would have been around to bandage her in this case, leading to her fainting of blood loss and dying, and tells Uryū that they should get moving before someone comes to investigate the noise generated by their crash.
Acknowledging this, Uryū runs off with Orihime as 7th Division 4th Seat Jirōbō Ikkanzaka steps out from behind some boards leaning against a nearby wall. Later, after watching 11th Division Captain Kenpachi Zaraki run off to another location with his lieutenant, Yachiru Kusajishi, upon finding a dead end near their own location, Orihime and Uryū poke their heads over the ridge of a nearby roof before expressing relief at them being gone. With Orihime observing that Kenpachi and Yachiru did not notice them despite seeming strong, Uryū theorizes that they are strong with low spiritual detection abilities like Ichigo as he wonders where they should go now. When Orihime points toward the Senzaikyū in the distance and suggests that they go toward the tower, Uryū turns toward her while picking up on her mention of a tower, only to be shocked upon seeing Jirōbō standing behind Orihime and swinging his Zanpakutō toward her.
Smashing his Zanpakutō into the section of the roof where Orihime was standing, Jirōbō realizes that she is no longer there and looks behind him to see Uryū holding a stunned Orihime, which prompts Jirōbō to praise Uryū's reflexes in saving her from such a close-range attack before proclaiming that he will give them time to feel regret for encountering him because they would have lived much longer had they not. Jirōbō stares down Orihime and Uryū as he counts to ten while holding his Zanpakutō horizontally in front of him. Upon realizing that Uryū is still holding her, Orihime assures him that she is okay, which Uryū acknowledges as he lets go of her. As she looks at Uryū, Orihime notes that his expression is different from before and recalls how he briefly disappeared from her senses and saved her from Jirōbō before she even knew he was there.
As she observes that he has undergone such a drastic change just from facing a Shinigami because they are still the enemies of the Quincy like Yoruichi told her, Jirōbō finishes counting to ten and inquires if they were able to regret sufficiently. With Uryū noting that the battle is about to start, Jirōbō proclaims that they will soon have all eternity to regret as he swings his Zanpakutō down at Uryū and Orihime. Jirōbō's attack cuts through the roof in a torrent of force as Orihime and Uryū leap away on either side of him. Summoning Tsubaki, Orihime fires him at Jirōbō and attempts to use Koten Zanshun, but Jirōbō contemptuously slashes through Tsubaki mid-flight, sending him flying back with a gash in his shoulder as Orihime frantically calls out to him. Upon being caught by Orihime, Tsubaki merely criticizes her for her poor attack power and returns to her hairpin.
With Orihime left confused by this, Jirōbō appears behind her and admits that he has never seen such a move before stating that he could not sense any murderous intent behind her attack. As he asserts that Orihime cannot kill a Shinigami with such an attack even if it works on Hollows, Jirōbō mocks her for thinking this is a playground and declares that she cannot accomplish anything with an attack that lacks murderous intent as he brings his Zanpakutō down onto her, only to be interrupted when a Heilig Pfeil slams into his hand, pushing his blade away from Orihime and wounding the back of his hand. With Jirōbō stunned by this, Uryū informs him that he can find plenty of murderous intent in his bow as he stands with the new version of his Heilig Bogen, Kojaku, formed and with steam trailing from his fingers. Seeing this, Jirōbō inquires if Uryū is a Quincy, which the latter confirms as Orihime stares in astonishment.
While Orihime mentally observes how much Uryū's Kojaku has changed in its physical appearance and Reiatsu and realizes that Uryū trained by himself in order to learn how to handle the Sanrei Glove that Kojaku is attached to, Jirōbō chuckles and claims that it will be fun to face a Quincy and a girl with mysterious abilities, which he considers a happy coincidence of fate to have both of as his opponents, before proclaiming that he will show Uryū the true form of his Zanpakutō while releasing his Shikai, Tsunzakigarasu, causing the blade of his Zanpakutō to separate into dozens of spinning, radially symmetrical, dual-edged blades that begin whirling through the air around him as he places the hilt of his Zanpakutō into its scabbard.
Jirōbō tells Uryū and a shocked Orihime to feel regret and introduces himself as well as his moniker of Kamaitachi, which he explains is the mark of the ultimate weapons master because no one other than him has ever seen these blades flying through the air and lived. However, while Jirōbō asserts that Uryū must regret meeting him as a fellow weapons master due to how terrifying Tsunzakigarasu is, Uryū instantly destroys all the flying blades of Tsunzakigarasu with dozens of individual Heilig Pfeil fired all around Jirōbō, who is left stunned, and observes that the weapons masters of Soul Society like to make long and boring speeches unlike those in the Human World. Though Jirōbō nervously claims that this was just luck and begins to recreate his blades by pulling his hilt back out of his Zanpakutō's scabbard, Uryū states that he still does not get it and fires another Heilig Pfeil that shatters the newly-formed blades and part of Jirōbō's hilt as it tears out a chunk of his hand, causing him to scream in pain.
Explaining that Jirōbō will no longer be able to call himself ultimate after today because he is far superior in weapon mastery, Uryū notes that he does not like the way Kamaitachi Uryū sounds. Jirōbō clutches his damaged hand by the wrist and screams in pain while a stunned Orihime notes that Uryū is completely different from the young man who fought Ichigo before. As Jirōbō pants and sweats heavily, Uryū approaches him and inquires if Jirōbō is feeling some regret now as a weapons master who had the misfortune of meeting Uryū. Angered by this, Jirōbō turns to Orihime and moves to grab her while reiterating his claim that Uryū is the one who will feel regret, only for Uryū to move between the two of them with Hirenkyaku and question if Jirōbō planned on attacking Orihime or taking her hostage out of desperation.
Drawing back another Heilig Pfeil in Kojaku, Uryū observes that Jirōbō has been after Orihime from the very beginning and dismisses the idea of him endangering her by accident due to being clumsy before asserting that no one with a shred of honor fights in such a manner. Uryū bids Jirōbō farewell while noting that it would be a waste to allow him time for regret, and as Jirōbō screams in terror, Uryū shoots him in the chest with two Heilig Pfeil, sending Jirōbō flying back.
As Uryū retracts Kojaku and stares at his steaming Sanrei Glove, Orihime thanks him and finishes his sentence when Uryū begins to bashfully claim that it was nothing, leading her to smile at his surprised stare. When Orihime asks him if Jirōbō is dead, Uryū denies this and explains that he simply destroyed Jirōbō's Saketsu and Hakusui, which will allow him to live but result in him losing his spiritual powers forever and likely never being a Shinigami again. After declaring that the battle is over, Uryū tells Orihime that they should go, and the two begin walking away as Orihime recalls Yoruichi Shihōin's explanation of how Quincy fight by gathering Reishi.
Observing that Uryū's Sanrei Glove must increase his ability to gather Reishi, Orihime realizes that Uryū trained alone because he did not want to hurt them in the process of learning to control such power, and as she expresses amazement at him being able to control this power and fight so well after just ten days of training, Orihime somberly wonders what she accomplished in those ten days because she does not feel any stronger at all.