“Anyone who can make kaiju is a kaiju themselves,” says Alexis Kerib, after transforming Akane herself into an enormous monster that wails out a terrible lament as it destroys what’s left of the city. Still temporary allies, Gridman (dwelling in Yuuta) asks Anti to deal with the Akane-kaiju, as he and Rikka have something else they need to do.
Akane isn’t feeling particularly good about herself, which is probably what enables Alexis to transform her and control her so easily: he thrives in the corruption of the heart, in hatred, disgust, and aloofness. He chortles when Rikka calls Akane “her friend” not because Rikka is only Akane’s programmed creation, but because he doesn’t believe there even is such a thing as friends.
Right on cue, Rikka’s friend Yuuta-Gridman picks her up in Sky Vitter (to Alexis’ bemusement), and they return to the hospital to snap Shou out of his funk. Regardless of how useless or normal he thinks he is, Yuuta tells him that Junk needs everyone there to work. The Gridman Alliance is more than just a cool nickname for their little circle, it’s the key to unlocking Gridman’s full power.
Anti succeeds in freeing Akane from her kaiju prison (which seemed to be filled with some kind of clear LCL), but Akane wonders why he bothered with someone as terrible as her. Anti fully owns his “failed creation,” since the fact he failed meant he’s more than just a kaiju, but a human.
Alexis makes no distinction between kaiju and human, or anything else, since to him it’s all below him. Because Akane is still in a bad state, he exploits her negative emotions and literally consumes her to become a kind of “Alexisman”—but the Alliance are back at the Junk Shop, and when they activate the new acceptors that appear on their wrists, a new, final form of Gridman appears: less armored and more like, well, a giant guy in a suit.
This new Gridman fights Alexis in order to free Akane once more, and has some success…until the halved Alexis simply auto-repairs. He is immortal and infinite, so however many times Gridman tries to destroy him, he will just keep coming back forever. Since Alexis has everything “of value” in Akane’s world—that is, Akane herself—he decides to head back to his realm…after killing Gridman.
But before he can skedaddle or kill Gridman, Gridman discovers a new power, and possibly his most important: The pink Grid Fixer Beam, which repairs not only the city Akane created and then destroyed, but succeeds in rescuing Akane’s heart from Alexis’ clutches. The Fixer Beam basically deletes him from the world.
Finally, free, Akane worries about what comes next. “A big world’s too much for me!” she laments, because she’s such a weak, pathetic coward. Rikka, Yuuta, and Shou tell her that no one’s perfect, which is why they—which is why everyone—relies on others.
Her world afforded her godhood and a kind of immortality, but it’s run it’s course, and now it’s time to return to the world of mortality and the finite. Akane’s grateful to Rikka for saving her, but also wracked with guilt over the things she’s done that cannot be undone with any Fixer Beam.
Rikka tells her not to sweat it, and gives her the gift of a wallet that matches her own (and also happens to be the same color as Akane’s hair). Rikka wants Akane to stay in the world and be together with her, but tells Akane not to let that wish come true. No one can force Akane to leave; she has to want to do it; to return to her real life.
With that, Akane disappears from Rikka’s side. Gridman & Co. say their goodbyes to Rikka and Shou before returning to the Hyper World, and not long after that Yuuta wakes up in the junk shop, the Gridman Alliance now just a friendship of three kids. The puckish humanoid kaiju who once guided Yuuta heals Anti, who is grateful, and now sports both a human and a kaiju eye—his past and present.
Finally, in the real world—as in, a live action world—a girl with long black hair much like Rikka’s slowly wakes up and rises from the bed, the Akane-colored wallet on her dresser. This, it seems, is the Real Akane, who left the world where she was a god (i.e., her dreams) and returned to the world she thought she couldn’t handle.
Now the ending with Rikka and Akane makes more sense: Akane made the purple-haired Akane to be her ideal avatar, and made Rikka, who more closely resembled her real-life self, to love her. Ergo, in her world, she loved herself. But Rikka taught her the power of friendship, and the need to wake up from dreams and not sink into Alexis-like abysses of darkness and despair.
A lot of this might sound corny, but the show expresses these well-worn ideals so earnestly and powerfully, it all comes together and works pretty well, which can be said of the show as a whole. Despite only catching a tiny portion of the references to Gridman and Gridman-esque works, SSSS was never not a pleasure to watch and listen to.
The ending could be said to be too neat and tidy, squandering a universe of potential alternate directions. But at the end of the day the lesson holds: just as friendships have value because we aren’t infinite or immortal beings, an imperfect finite ending will do just fine.