After the giant rogue iDOL is defeated by Makoto, Haruka is given an offer she can’t refuse: to become an iDOL Master. Her friend Yayoi is convinced that the organization is swindling her, and leads her on a wild goose-chase trying to track down the truth.

Haruka begins to settle into her new life, attending classes at the high school that is a cover for the Mondenkind iDOL organization.

Iori has failed to destroy a meteorite, merely splitting it in half so that there are now two targets to destroy. When Haruka saves the day, it only exacerbates Iori’s rivalry with her.

After Yukiho and Haruka fail an exam, a retest is planned by Asuza that stresses them both out. When their studies don’t go very well, an annoyed Iori steps up to coach them.

Haruka is deployed to handle two Lemon-class meteorites, but the targets suddenly disappear – only for more bogeys to suddenly show up on Mondenkind’s sensors.

Chihaya is determined to get the Imber back, even if it costs Haruka her life. While Mondenkind deals with the crisis, Haruka winds up in the infirmary, having lost consciousness.

Haruka and the others are at the beach, but this is no vacation – they are performing activation tests and pilot training for Imber and other iDOLs in the same town where Imber and Nebula were manufactured.

The girls are sent to find an idol, Ami Futami, who used to be a mechanic for Mondenkind, and ask her to come back as a consultant.

The iDOLs and their pilots go through harmonization, fine-tuning the machines to match their pilots. Iori’s numbers are the best she’s ever attained, pushing Makoto out of being Nebula’s master.

Haruka and Ritsuko are in Iceland hunting for one of the lost iDOLs. Chihaya has also gotten her hands on this intel, and Turiavita deploys her.

Mondenkind searches for Haruka, who happens to be with Chihaya but does not recognize her. Makoto foolishly takes off on her mission, desperate to prove herself the top-performing iDOL Master.

Makoto is completely out of sync with Nebula, but refuses to see her treatment of it as being the underlying cause.

Iori is sent out as Nebula’s pilot, charged with setting up two early-warning satellites in space. But this routine mission is just an excuse to try out some covert experimentation with the iDOL.

Imber goes berserk. Mondenkind tries everything they can think of to stop him, but to no avail. It seems they’ll be forced to make him self-destruct.

Haruka has found a video of Chihaya in one of Imber’s files that shows he abandoned her after being in harmony. She loses confidence in their relationship, wondering if the same thing could happen to her.

Saku leads the investigation into the identity of the mole at Mondenkind, and Yukiho keeps attracting his eye.

The Turiavita have launched a surprise attack on Mondenkind’s base in Tsukimijima. They ransom Ami in exchange for Nebula and Imber.

Haruka has lost Imber, while Nebula is busy fighting off Riffa. With all five iDOLs in Turiavita, Mondenkind must destroy the iDOLS with a shot from Vulturius – even if it costs millions of lives.

Ami and Mami are safe back in Mondenkind’s Japanese base, though Tempestas sacrificed all his memories to save them. Yukiho and Imber, however, did not return, leaving Haruka grieving.

Depressed by the betrayal of Yukiho and Imber, Haruka locks herself in her bedroom. Joseph begins an investigation into who is really running Mondenkind.

Saku relocates almost all the staff from Mondenkind Japan and puts the base on lock down. It’s up to Joseph to gather people back together and take back the base.

Mondenkind Japan must fend off Turiavita’s onslaught and buy enough time for Haruka to talk to Imber. Haruka confesses her feelings to Imber, but will he accept or reject her now that he has Chihaya once more?

Azusa infiltrates Turiavita’s headquarters and discloses the information with Mondenkind and various countries. At the same time, Chihaya undergoes the preparations necessary to become one with Imber.

Haruka goes to Turiavita’s headquarters to confront Yukiho and Chihaya one last time. But with a horde of Epimetheus units blocking the way, the going won’t be easy. Lucky for Haruka, she doesn’t have to do it all on her own.

Auryn has grown unstable after absorbing Nubilum. If something isn’t done soon, the entire planet will be destroyed! The iDOLs are willing to sacrifice themselves to save the ones they love, but how do their Masters feel about this?