A student at Mizuna Girls' Academy, Tsukuyo, is hiding the fact that she is a member of the Wings of the Magius. Iroha goes to see Tsukuyo and asks to be introduced to Nemu Hiiragi, a friend of Iroha’s sister, Ui. Tsukuyo promises to Iroha that she will talk to Mifuyu about the matter. Sana has gotten accustomed to living at Mikazuki Villa, and suggests to everyone that they surprise Yachiyo with a gift, but…

With Yachiyo in low spirits, Iroha and company leave her behind and head for the Memory Museum. Touka Satomi, a friend of Iroha’s sister, Ui, awaits them there to give them a lecture about the truth of Magical Girls. Yachiyo’s past memories give her a push, and she decides to go find Iroha. However, at that very moment Iroha is already in the midst of a "vicarious practical learning" course prepared by the Magius.

Iroha refuses to join the Magius. When she and Yachiyo meet up, she is eager to go search for Tsuruno and the other girls. However, Yachiyo believes that her wish brings tragedy to those around her and tells Iroha that she is disbanding the team. The Memory Museum begins to collapse. Iroha and Yachiyo try to escape, but Mami, who has become an entirely different person, attacks them.

Yachiyo and Kuroe find Iroha inside the Labyrinth of the Uwasa of the Eternal Sakura. However, Yachiyo and Kuroe are swallowed by the Doppel of Silence that suddenly appears from Iroha’s body. When Yachiyo awakens, she finds herself at Mikazuki Villa eating breakfast with Tsuruno, Felicia, Sana, and Iroha, but Kuroe, who is not supposed to be there, is in the room with them. Yachiyo and Kuroe are baffled by the situation they are in, but they have a hunch that they are not in the real world, but in a dream world being shown to them by the Doppel of Silence. They are concerned about Iroha’s safety in the real world, so they do all they can to wake up Iroha in the dream.

Iroha embarks on a journey to find her friends from Mikazuki Villa. Kuroe is genuinely concerned about Iroha so she decides to tag along. Meanwhile, Felicia and Sana are working inside of the Magius as Black Feathers. Felicia proclaims that she will not return to Mikazuki Villa until she finds out how they can avoid becoming witches. Sana begins to question the actions of the Magius while she manages the people captured by the Uwasa,. Mifuyu, who is acting as a White Feather, finds herself in a predicament when she reunites with an unexpected person. Amidst the intricate tangle of everyone’s emotions, Touka announces her strategy to save all Magical Girls. What could it be?

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.

To fulfill their promise to Ui, Touka and Nemu set their plan in motion with Embryo Eve. Yachiyo desperately tries to stop them. As Alina watches events unfold, Kuroe is isolated and alone. And Kyubey is not far behind… Meanwhile, Iroha wakes up in her room at home. Everything looks the same as when Ui was still around. Finally, Iroha is reunited with Ui.