Captains Kenpachi Zaraki, Byakuya Kuchiki, and Tōshirō Hitsugaya run across the streets of Seireitei, stopping abruptly to sense massive Reiatsu flooding throughout the area. Kenpachi comments that their enemies are aware of their presence, attempting to head out. However, Captain Hitsugaya stops him in his tracks, as Kenpachi is surprised at this. Hitsugaya states that they will have to fight against the Reigai regardless, explaining that their only target as of right now is Kagerōza Inaba. 
He tells the two captains to split up, in order to get to the 12th Division barracks individually. Kenpachi agrees with this plan, as Lieutenant Yachiru Kusajishi appears upon his shoulders, directing him forwards. He states that he knows where he is going, as Hitsugaya tells them to meet up at the 12th Division's headquarters. The three captains then head off in opposite directions, as Hitsugaya senses the Reiatsu emanating from Kenpachi's path, realizing who it belongs to. 
As it begins to rain, Kenpachi makes his way up a flight of stairs, approaching his opponent. Yachiru wonders whether it truly is his Reigai counterpart, to which Kenpachi confirms this. Kenpachi greets Reigai-Kenpachi, stating that he was eagerly awaiting his arrival, to which the Reigai smirks in response. He comments that it is as if the Reigai can read his mind, but he denies this. Reigai-Kenpachi asks why he is here, to which Kenpachi reveals that he wanted to find out how strong he truly is. 
The Reigai comments that he truly can read his mind, removing his eye patch. Kenpachi wields his katana, stating that he doesn't mind losing, so long as the other is stronger. He tells Yachiru to seek shelter, to which she clambers up a tower, observing the battle.
Kenpachi then tells his Reigai counterpart to make their battle fun, removing his own eye patch. He releases a tremendous amount of Reiatsu, which Reigai-Kenpachi emulates, the conflicting forces rippling into the sky. Both Kenpachis smirk at each other, as Yachiru notes that they are both very similar. Kenpachi tells his counterpart not to hold back, otherwise he will die. As he charges at Reigai-Kenpachi, the counterpart states that he will be the one who dies, as the two begin their violent clash. 
Kenpachi and the Reigai lock blades, pushing each other away. The original leaps down from an alcove, successfully cutting Reigai-Kenpachi's chest. He staggers backwards, blood surging out from his injury. Kenpachi asks what the matter is, stating that he thought a Reigai was meant to possess far greater power than the original. He tells Reigai-Kenpachi not to disappoint him, prompting the Reigai to reassure him, stating that the battle is far from over. Kenpachi is surprised at this statement, whereupon a similar gash appears upon his chest, as drops of blood begin to drip onto the ground. 
He touches the wound, commenting upon his sheer strength. Kenpachi then charges at his Reigai opponent. He attempts to cut Reigai-Kenpachi once more, but his blade is knocked away effortlessly. Reigai-Kenpachi comments that it was a nice ploy, proceeding to grab his head and throw him into a nearby wall. As the debris falls around the battlefield, Reigai-Kenpachi explains that he will retract his previous statement, stating that he no longer wishes to lose to a weak opponent like him.
Kenpachi laughs wildly, breaking free from the rubble. The Reigai-Kenpachi asks why he is laughing, to which Kenpachi reveals that he is enjoying their battle. He jumps down from the ruins, asking the Reigai whether they share the same memories. He compares his battle to that of when he fought Ichigo Kurosaki, stating that he cannot help himself, rushing at the Reigai. Kenpachi brings his sword down upon the Reigai, both swords clashing together. He comments that it is a shame, proclaiming that he will be the one who enjoys this fight, if a Reigai truly is superior.
Kenpachi brings his sword down again, this time easily slashing the Reigai. Reigai-Kenpachi stumbles momentarily, purple sparks flashing from his eyes. Kenpachi tells him not to admit defeat, not when the fight is starting to become enjoyable. Reigai-Kenpachi states that he will not, and that he is starting to feel the way Kenpachi does. The two clash violently across the area, each being able to cut the other with ease. Kenpachi charges at his Reigai counterpart, their blades locking in mid-air. Reigai-Kenpachi roars, knocking away Kenpachi's sword with his own.
As Kenpachi is defenseless, the Reigai proceeds to run him through. He pulls his sword out from Kenpachi sadistically, who crashes to the ground uncontrollably. Yachiru cries out in protest, as Kenpachi stares lifelessly in front of him. Reigai-Kenpachi asks whether their battle is finished, to which Kenpachi does not respond. Kenpachi expresses his disbelief in the fact that he was defeated by himself, but states that he does not mind, as the Reigai proved himself to be stronger. His eyes then close, as Yachiru calls out to him.
He opens his eyes, as Yachiru appears over his immobile body. She calls out to him, allowing Kenpachi to reminisce back to their time in Rukongai. Kenpachi states that he understands, and that he had forgotten about their inseparable ties. He stands up again, releasing his yellow Reiatsu once again. Kenpachi explains that he cannot die, as Yachiru would be all alone. Reigai-Kenpachi turns to face him, asking what is he talking about. Kenpachi states that he will also retract his statement, explaining that he strives for victory.
He diminishes his Reiatsu with one strike, as rubble collapses once more over the area. Reigai-Kenpachi shields himself from the rubble, as Kenpachi wields his Zanpakutō with two hands. He reiterates that he wants to win, even if it is against an impostor like him. Reigai-Kenpachi refutes this proclamation, wielding his Zanpakutō with two hands also. He proceeds to charge at Kenpachi one final time, who stands his ground. As the two release Kendō, they are consumed within the explosion.
As the explosion ceases, a cloud of smoke billows from the area. Yachiru emerges, covering her eyes from the attack. As she opens them, she notices Kenpachi stumble to the ground. Yachiru calls out in concern for him, as he brushes this off. The dust then clears, as Reigai-Kenpachi emerges seemingly uninjured. He tells Kenpachi that he finally understands his motivation for fighting, falling defeated to the ground. His Zanpakutō clatters to the ground, as the Reigai disintegrates into dust. Kenpachi smirks, before falling to the ground himself. Yachiru runs over to him, asking whether he is dead, to which he refutes this. Yachiru then smiles.