Shūhei Hisagi vs. Kazeshini: Final Fight

Shūhei Hisagi vs. Kazeshini: Final Battle is the final conflict between Lieutenant Shūhei Hisagi and his Zanpakutō, Kazeshini. Kazeshini had continued to act independently even after being restored and freed from Muramasa's brainwashing by Captain Mayuri Kurotsuchi, with the intention of killing his Shinigami master.

Prologue
Lieutenant Shūhei Hisagi, 3rd Seat Ikkaku Madarame, Lieutenant Tetsuzaemon Iba & Lieutenant Izuru Kira go to investigate an area of Rukongai that has been attacked by several Tōjū. Kazeshini makes a surprise attack on the group along the way, as Hisagi tells the others to go on ahead while he deals with his Zanpakutō. Noting that Kazeshini hasn't changed at all, the Zanpakutō spirit asserts on how he will follow Hisagi wherever he goes until they finish their fight. Hisagi then releases his Shikai. As they fight, the two of them exchange retorts on what they do not like about each other; Kazeshini dislikes what he thinks is cowardice by Hisagi and Hisagi dislikes how Kazeshini does not fight head on. Hisagi ends up defeating Kazeshini but does not give the finishing blow, citing that he will only finish their fight when Kazeshini fights him head on.

Hisagi then catches up with the rest of his team at Rukongai. He learns that the Tōjū had already fled before their group arrived. As Kazeshini looks at Rukongai from a distance, he is visited by Haineko, Hōzukimaru, and Wabisuke. Haineko scolds him for damaging relations with the Shinigami. Hōzukimaru asks why Kazeshini is so hell-bent on killing Hisagi, to which Kazeshini tells him to mind his own business. Haineko then tells him that they do not care on what he does, so long as he does not drag the rest of the Zanpakutō spirits down with him. Hōzukimaru also shares the same sentiments, saying that he will not get in Kazeshini's way but will not help him either.

A Tojū then begins attacking Rukongai again, as Hisagi arrives to handle the attacker. He is able to injure the Tōjū and is in pursuit when it tries to escape. Before he can go any further, Kazeshini reappears for another surprise attack, leaving Hisagi lightly injured in an attempt to protect the civilians from taking damage. Hisagi knocks Kazeshini into a building and leaves to continue fighting the Tōjū, leaving Kazeshini wondering why Hisagi is so concerned about others' well-being. Having lost sight of Hisagi, he leaves in search for his Shinigami master.

Babysitting an Infant
Kazeshini then comes across the same Tōjū that Hisagi was chasing. He finds that the Tojū has just cut down someone. Disappointed that it is not Hisagi, he moves to leave but is stopped by the Tōjū. The rogue Zanpakutō asks him who he is and states that Kazeshini is one of the Shinigami' "dogs", before Kazeshini can give an answer. The Tōjū then attacks but is cut down own by Kazeshini with little effort, annoyed that the Tōjū called him such a derogatory term. Upon exiting the hut, Kazeshini notices a baby staring at him. Before dying of his injuries, the Tōjū's victim begs Kazeshini to watch over his child. Kazeshini initially ignore his pleas and tries to leave the child, but flees with the child when the infant begins to cry and attracts the attention of Kira and Iba.

Less than pleased at the prospect of having to care for a child, Kazeshini tries to desert the infant. However, the child continues to latch on to him in joy and Kazeshini finds himself unable to abandon the child. He then meets up with the other Zanpakutō, as Haineko and Hōzukimaru make fun of him for having the baby on his back and Wabisuke is rather less enthusiastic. Kazeshini tries to get them to take the child off his hand but they decide to leave Kazeshini to his own devices. This news eventually reaches the vice-captains., as Kazeshini finds that the child's presence increasingly makes his attempts at fighting Hisagi difficult. Eventually, the infant falls asleep and Kazeshini places the child a safe distance away. He then finds the Lieutenants fighting the Tōjū gang and moves to attack Hisagi, but he hears the crying of the baby after a woman found the boy. He finds himself debating whether he should check on the crying boy, or make a surprise attack on Hisagi. He ends up going back to the infant and is surprised to see the woman trying to comfort the baby. The woman pleads with the Zanpakutō spirit, thinking that Kazeshini was another Tōjū. As the boy toddles towards Kazeshini, Kazeshini asks that the woman take care of the child. However, he is attacked from behind by a Tōjū. However, instead of evading the Tōjū's attack, he finds himself shielding the boy with his own body. This causes him to have some understanding on why Hisagi has concern for the well-being of others. He tells the woman to escape with the child, who obliges.

Battle
With the woman having left with the baby, Kazeshini returns to Hisagi to have his showdown head-on. They then begin to battle, both unleashing their Shikai. As their blades clash, Hisagi asks Kazeshini where is the child that was with him. Kazeshini quickly denies knowing anything about that. He flings one of his blades, which Hisagi is able to dodge. Kazeshini then pulls on the chain of the blade, causing the blade to come back at Hisagi's back. However, Hisagi is able to block the attack easily. They then cross blades again. Both of them are found to have injuries from fighting Tōjū but it does not stop either of them. Kazeshini then states that it is time for them for end things, which Hisagi agrees to. The two charge at each other and clash. Kazeshini, however creates an opening for Hisagi after briefly writhing in pain from the back injury inflicted by the Tōjū while protecting the infant. Hisagi is able to quickly slash Kazeshini and defeat him. As Kazeshini falls to the ground, he hears the child's crying and calls out to him, telling him "don't cry."

Having lost, Kazeshini asks if he will return to be being a normal Zanpakutō. Hisagi confirms this, which Kazeshini states he will not be very happy about. He then asks what will they fight for when he turns back to a normal Zanpakutō, as Hisagi tells him that they will fight to protect others together. Hisagi then states that Kazeshini must not like that, which Kazeshini agrees, half-heartedly says he will despise it, but he has no choice in the matter.

Aftermath
Kazeshini has some understanding on why Hisagi has concern for the well-being of others after his experience in protecting an infant. Kazeshini ends up returning back to a normal Zanpakutō after failing to defeat Hisagi. Several Tōjū are dealt with during the lead up to this battle.