The Magical Girls break into the headquarters of the Magius. After Iroha and Yachiyo reunite, they meet up with Madoka and the other girls, but are confronted by Tsuruno Yui and Mami Tomoe who have become soldiers of the Magius. Mami and Tsuruno, who are being manipulated by another entity, begin attacking the Magical Girls. Iroha and Madoka are in a bind as they are unable to fight back. As a tactic, the Magius summon countless Witches to gather in Kamihama City. The largest ever Supercell is approaching and will hit Kamihama City in six hours. The true identity of the Supercell is actually Walpurgisnacht, the most sinister and evil Witch ever.

It happened in the past… Iroha would go to the hospital daily and play with Ui, Touka and Nemu. The girls loved Iroha and looked forward to her visits. One day, the three girls create an Uwasa similar to an urban legend while playing. That way, if they died, the Uwasa they created would live on and remind Iroha of them. Iroha also created the “Uwasa of Eternal Sakura”, with the wish that the three girls will be discharged from the hospital without illness. And one day... Kyubey appears before Iroha.

The Magical Girls rush to Iroha while fighting against Uwasa of the Soldier Bear. The Amane sisters also stand in their way, but Mifuyu keeps them in check. "The plans of the Magius have failed." Meanwhile, Iroha and Touka regain the memories that Nemu's power took from them. Touka is happy to be reunited with Iroha but can’t recall why they became enemies in the first place. Nemu tells Touka why she had been hiding the truth until now. Now, they see the promise they made with Ui in a new light.