Ikkaku Madarame vs. Tetsuzaemon Iba

 is a fight taking place during the Ryoka Invasion between 11th Division 3rd Seat Ikkaku Madarame and 7th Division Lieutenant Tetsuzaemon Iba after they find themselves on opposite sides during Rukia's Execution.

Prelude
After being broken out of prison by 11th Division Captain Kenpachi Zaraki, Yasutora Sado, Uryū Ishida, and Ganju Shiba follow him, 11th Division Lieutenant Yachiru Kusajishi, 3rd Seat Ikkaku Madarame, 5th Seat Yumichika Ayasegawa, Orihime Inoue, and Makizō Aramaki to a large, empty pavilion atop a building in search of the execution grounds, where Uryū nervously observes that finding the right street seems to take luck as Orihime affirms that ten or twenty dead-ends is not uncommon. With Yachiru irritated by this, Ikkaku points to this as proof of why he did not want her leading them, leading Yachiru to angrily bite his head in response.

Suddenly, Yumichika senses an intense Reiatsu in front of them, and upon being alerted of this, Kenpachi criticizes such sneaking around and demands that they show themselves as he claims that captains should not be concealing their Reiatsu. Berating Kenpachi for his arrogance and questioning if he knows what he is doing, Tōsen appears on the rooftop in front of the group alongside Komamura, Iba, and Hisagi. As Tōsen inquires where Kenpachi is going with the Ryoka and if lost his honor when he was defeated, a terrified Aramaki identifies him, Komamura, Iba, and Hisagi while expressing disbelief at being confronted by four powerful opponents like this.

However, though Yumichika assures Aramaki that they are outnumbered by the Ryoka's group and Aramaki asserts that it is not about numbers, Kenpachi tells them to be quiet and reminds Yumichika that he never said he would let the others fight before declaring that he will be fighting all four of the Shinigami at once, though he does not believe it will be enough to test his sword. Moving to the ground alongside the others, Komamura picks up on Kenpachi's comment about testing his sword and inquires if the latter intends to fight all four of them at once. With Komamura asserting that he may be overrating himself despite his impressive skill, Kenpachi exerts his Reiatsu as he draws his Zanpakutō and demands that they fight instead of talking before advising them to attack from all sides at once so one of them might have a chance at cutting him.

After Yachiru seemingly leads the others away, Iba and Hisagi approach Kenpachi as they request that their captains let them take care of this, and as a disappointed Kenpachi reminds them of his advice to attack him all at once, Ikkaku echoes his criticism and declares that he knew it would be like this before appearing in front of Kenpachi alongside Yumichika, who asserts that they will have to step in if this is how Iba and Hisagi want to do things. Though Kenpachi is confused as to why they are still here, Ikkaku berates Iba and Hisagi for thinking they would have the privilege to take on a captain despite being only lieutenants, and after Kenpachi realizes that they want to fight as well and orders them to do so somewhere else at risk of being killed if they get in his way, Ikkaku and Yumichika comply.

When Iba questions when Ikkaku gained the right to speak to him like this, Ikkaku claims that he does not need lessons on how to talk from a coward who left the Eleventh Division because he could not become the lieutenant, leaving Iba visibly irritated by this, though Ikkaku tells him to save this for later and to go somewhere else because he does not want Kenpachi to kill him, which Yumichika echoes. Upon being requested by Yumichika to go somewhere else with him, Hisagi asserts that it will not matter regardless of what he does, and Ikkaku, Iba, Yumichika, and Hisagi all disappear with Shunpo.

Battle
Some time later, in a clearing within the forest surrounding Sōkyoku Hill, Ikkaku observes the lightning that occurred nearby and claims that it would have struck them had he swung his sword, prompting Iba to berate him for not realizing this was actually Kidō and that they are in no danger because it was aimed at something else while drinking sake from a gourd. When Iba tosses the gourd to him and admonishes him for not learning how to perform Kidō, Ikkaku catches the gourd and drinks from it as well as he sits against a tree and asserts that spells are simply not his style. While Ikkaku claims to have not been born with versatile powers like Iba was, Iba clarifies that he was not born like this either.

With Iba asserting that he simply trained for versatility because one is more likely to become a lieutenant if they are well-rounded than if they are simply proficient in one area of combat, Ikkaku comments that this does not sound like much fun as he tosses the gourd back, prompting Iba to declare that a man should aim to rise through the ranks and that it is indeed fun while catching the gourd. However, Ikkaku counters that this is merely what Chikane Iba wanted, though Iba questions why he would want to be a lieutenant for a witch like his mother. Suddenly, as Ikkaku begins to address something, Iba observes that they are out of sake, prompting a shocked Ikkaku to berate Iba for drinking it too fast, and when Iba states that sake is subject to the laws of nature like everything else, Ikkaku inquires if he is implying that the sake evaporated.

After agreeing to do it once again, Ikkaku and Iba repeatedly play janken until Iba wins, at which point he moves to the top of the nearby cliff while attributing Ikkaku's loss to him being bad at janken. Suddenly, the two of them hear a loud explosion of force on Sōkyoku Hill, leading Iba to inquire who is fighting 6th Division Captain Byakuya Kuchiki because he does not recognize the Reiatsu. Upon being told that it is likely Ichigo Kurosaki, Iba asks if he is from the Eleventh Division, only for Ikkaku to question why someone from the Eleventh Division would be fighting Byakuya and clarify that Ichigo is a Ryoka whom he fought once before.

With Iba commenting on how Ichigo must be strong and that it would be fun to fight someone like that, Ikkaku notes that Iba is a warrior to his core and picks up his Shikai, Hōzukimaru, while declaring that it is time that they picked up where they left off. Affirming this, Iba holds up his own Shikai and reminds Ikkaku that whoever loses has to get more sake, and after Ikkaku continues that whoever wins gets to rest, the two of them conclude that easing up will result in death before resuming their clash.

Aftermath
After 5th Division Captain Sōsuke Aizen sets his endgame into motion, 4th Division Lieutenant Isane Kotetsu informs the combatants within the Seireitei of his plot and betrayal, leaving Ikkaku and Iba stunned by the news of the Central 46 being murdered. Later, Iba confronts Aizen on Sōkyoku Hill alongside several other captains and lieutenants, where he appears next to a wounded Komamura.