Ikkaku Madarame vs. Tetsuzaemon Iba

 is a fight between 11th Division 3rd Seat Ikkaku Madarame and 7th Division Lieutenant Tetsuzaemon Iba taking place during the Ryoka Invasion.

Prelude
As the 11th Division captain and its members, assisting the Ryoka, search for Ichigo Kurosaki, Yumichika Ayasegawa and Kenpachi Zaraki sense an ominous presence, indicating there is someone hiding nearby. When Kenpachi tells them to come out, Captains Sajin Komamura of the 7th Division and Kaname Tōsen of the 9th Division show themselves, along with their respective Lieutenants Tetsuzaemon Iba and Shūhei Hisagi.

As the others in Kenpachi's group are surprised to see them, Tōsen asks why Kenpachi is aiding the Ryoka. As Yumichika tells Makizō Aramaki they have them outnumbered for a fight, Kenpachi states he will be the only one fighting by taking them all on. When Komamura and Tōsen state Kenpachi is too prideful, Kenpachi insists they all come at him at once. As the rest of the group wonders what to do, Yachiru Kusajishi tells Kenpachi the rest of them will continue on as he fights. As Kenpachi says he will catch up to them, Tōsen states he cannot be serious, and he must have lost his pride and his sanity, prompting Kenpachi to state he never had any sanity to begin with. While the group runs ahead, both Hisagi and Iba, stepping forward, offer to fight Kenpachi first. As Kenpachi grumbles about how his opponents are looking down on him by not coming at him all at once, Ikkaku Madarame and Yumichika step in. As Kenpachi asks the two why they did not leave with the others, Ikkaku tells the lieutenants they are not good enough to fight their captain, so he and Yumichika will be sufficient opponents. Seeing that his two officers wanted to fight as well, Kenpachi lets them have Hisagi and Iba as opponents. Ikkaku is called out by Iba, who, stating it has been some time since they last saw each other, notes how much of a loud mouth Ikkaku has become. Stating he is the one to talk, Ikkaku, noting Iba left the 11th Division because he could not become lieutenant, motions for them to move to another location so as to avoid being injured by Kenpachi. All four of them leave.

Battle
As both combatants are resting and drinking sake with each other, Ikkaku, noting a lighting strike, says it would have hit them if they had raised their Zanpakutō up when it occurred. Iba scolds him for being ignorant, for it was actually Kidō and not a lightning strike, so it would not have reached them due to being a targeted attack. As Iba states Ikkaku has not improved one bit, for he still knows nothing of Kidō, Ikkaku, telling Iba he was never interested in Kidō anyway, states unlike him, his mother did not make him a "do-it-all" type of guy. Iba states he was not always like this, but because his goal was to reach lieutenant rank, being well rounded instead of focusing on only one skill meant a better chance at a promotion to that rank. When Ikkaku comments on Iba's tone not sounding happy, Iba states happiness is the only thing a man feels when he is promoted so quickly. When Ikkaku points out Iba's work being all for his mother, Iba disagrees.

When Iba points out there is no more sake, they engage in a brief argument over Iba allegedly always drinking too much of Ikkaku's sake. Having a few rounds of Jan-Ken-Pon (Rock-Paper-Scissors), the two notice the Reiatsu coming from Sōkyoku Hill. When Iba asks Ikkaku who is fighting Captain Byakuya Kuchiki, for he does not recognize their Reiatsu, Ikkaku tells him it is probably Ichigo. When Iba asks if he is an 11th Division member, Ikkaku, stating he is a Ryoka, comments on the absurdity of an 11th Division member fighting Byakuya. As Iba talks to himself about how strong Ichigo is and how nice it would be if he could fight him once, Ikkaku notes deep down, Iba is still a member of the 11th Division. They fight again, with the loser having to go acquire more sake.

Aftermath
The fight is later interrupted and halted by Isane Kotetsu, who, using Tenteikūra, informs them of Sōsuke Aizen's betrayal.