It was a time of peace, the time everyone had always dreamed of; one in which science had solved every problem.
Thanks to the invention of the Manifestation Engine, the world's energy problems had been eliminated.
Akane Isshiki, an innocent 14-year-old girl,
had been living an impoverished, yet rich, life with her little sister, Momo, and their grandfather, Kenjiro.
One day, Akane received word that her best friend, Aoi Futaba, was returning, but Aoi gets caught in the crossfire when
mysterious beings called the Alone suddenly appear and attack while she is on her way home.
Worried about her friend, Akane rushes out to meet her friend, but then...

Akane has donned her Palette Suit.
When told by her grandfather, Kenjiro, that they'll never be able to defeat their unknown enemy, the Alone, unless they dock, Akane and Aoi become bound and determined to to just that.
Aoi transforms into her Palette Suit, too, and confronts the Alone with Akane!
Working the the National Guard, they somehow manage to halt the Alone's advance.
Then, when they try to dock to finish it off while it's pinned down...

Akane, Aoi, and Momo have all been transferred to the school on Blue Island.
Running late for her first day of school, Akane transforms into her Palette Suit and flies there.
However, she is spotted by Kendo Club president Wakaba Saegusa!
Mistaking Akane for a criminal, Wakaba tries to subdue her, but her attacks are nimbly evaded.
Wakaba is unable to shake off the shock of being defeated by this unknown enemy.
And then, among the transfer students introduced at that morning's school assembly, she sees...!

Himawari Shinomiya, a girl who has become a shut-in as a result of some incident.
She observes everything by hacking cameras across the island.
On one such day, she witnesses Akane and the others fighting an Alone!
Unaware of this, Akane and the girls accidentally smash a webcam that Himawari had left on her desk.
Akane, Aoi, and Wakaba go to Himawari's house to apologize.
Himawari had planned to pretend to be not be home,
but the sight of Uso-kun intrigues her, and she invites them to her room, but then...

While delivering newspapers, Akane spots a girl playing with birds on an embankment. It is her classmate, Rei Kuroki.
Akane calls out to her, but Rei rudely ignores her and leaves.
Even when Akane sees her again at school, Rei feigns ignorance about that morning,
and that same day, Kenjiro and Shijo, who are analyzing combat data at the Manifestation Engine Administration Bureau,
realize that there is a possibility that the Alone are being controlled by some third party.

Akane and the girls have come to Shikine Island for summer school.
Mizuha has taken their Operation Keys for safekeeping to make sure they don't lose them in the water,
but the real purpose was for a special training program that Kenjiro devised.
His plan was to boost the strength of the girls' friendship power,
but by sheer coincidence, he is spotted by Rei, and she gets mixed up in their special training.
What will the results of this grandiose training program be...?

Akane had been dealing with the series of Alone attacks,
but her daily part-time job and Alone response were beginning to take a toll on her studies.
She is disciplined by the school, and if she doesn't get a good grade on her next proficiency exam, she'll be forbidden from working, and will have to take extra classes every day after school...
That being the case, Aoi and the girls propose that they hold a study session at Akane's house to help her study for the test.
Plus, Aoi and the others invite Rei to the study session, but she...

Akane is injured by an Alone attack. Aoi, Wakaba, and Himawari watch over her in the hospital.
Meanwhile, the Alone they thought they had defeated spins a cocoon and begins to regenerate.
The military's weapons can't so much as scratch the cocoon, and inside, the Alone continues to regenerate and grow.
As the deadline for the cocoon's hatching draws near, the government and UDF are confronted with the decision to launch a large-scale attack.
Also, Aoi and the others strengthen their resolve to fight the Alone in order to do what Akane would want them to do.

Wakaba has been having fun, coming over to Himawari's every Sunday to clean
and making her put on cute dresses.
When she takes Wakaba to the mall in a dress, Wakaba revels in the attention that Himawari is getting from all quarters,
but Himawari is mortified and tries to hide.
A writer for a popular fashion magazine comes up to Wakaba and Himawari
and asks if they can take some pictures of her for their readers' modeling section.
Himawari starts to refuse, but Wakaba beats her to the punch and agrees, and then...

Rei, whose Alone attacks have been thwarted again and again,
decides to use all her power on the next Alone in order to destroy the Manifestation Engine.
Rei visits Akane's house to try to find any clue, however small, to go about doing that,
and touched by Akane's frankness, she opens up about her own feelings.
Meanwhile, Kenjiro and Himawari have figured out what is happening in the instant
that the Alone have been strengthened.
And then, when she chases after the next Alone to appear, Akane finds...

Akane, Aoi, Wakaba, and Himawari stand before Rei. The five are astonished to learn each other's true identities.
Having been taken into custody and subjected to various tests, Rei is revealed to have come from another world.
Kenjiro explains how she is the cause of the appearance of the Alone.
Akane and her friends, unable to meet with Rei, go through her room and each talks about how they feel.
Then, determined to talk to Rei again, they head for UDF headquarters.
There, Rei finally begins to open her heart when Akane presses Rei with how she feels about her, but then...

The raven has swallowed Rei whole.
Boasting that he is now superior to "Them," he unleashes his overwhelming power.
And then, in an attempt to bring about the end of our world,
he makes for Blue Island to absorb the Manifestation Engine's energy and trigger a runaway.
Kenjiro and the others are battered by this enemy that is impervious to even SGE bombs.
However, Akane and her friends, believing in the possibilities of friendship, fly off in pursuit of the raven in order to save Rei.
Off to a battlefield where their feelings and beliefs will be put to the test...