The crew of Fraxinus sets about preparing for their battle against DEM with haste and high morale. The Spirits work hard to prepare snacks in order to encourage Shido and everyone else as the decisive battle draws closer by the hour...

A full-scale confrontation between Shido and his friends Ratatoskr and DEM has begun. Kurumi and her clone, AST led by Ryoko Kusabe, join them, and as the battle intensifies, Shido confronts a horde of pseudo-Spirits, Nibeelcole.

A certain time, a certain place. Shinji Takamiya encounters a spatial earthquake, but finds a girl at the scene. She remembers almost nothing about herself. Shinji gives her the name Mio and she goes to live with him and his younger sister, Mana.

Shido is flooded with memories as the girl named Mio Takamiya stands before him. She was the person with whom Shido once shared his feelings when he was Shinji Takamiya. Meanwhile, Kotori and the others learn of Reine's true identity.

As Shido rushes to the Spirits' side, Westcott blocks his path. Meanwhile, Tohka and the others find themselves overwhelmed and powerless before Mio's manifested Angel, Ein Sof Ohr.

Many spirits were exhausted by Mio's Ein Sof Ohr and collapsed. Kotori directs Fraxinus toward Mio and fires her spirit cannon, Gungnir, but...

Shido is shocked when Mio tells him that all the Spirits are dead. Stunned and unable to move, Mio nearly wipes his memories as Shido, but there is still one Spirit who's survived.

Shido returns to a time before the final battle with DEM began, when no one has died yet. In order to avoid repeating the same future, Shido asks Reine out on a date. After hearing the story from Shido, Kotori and the Spirits support their date.

As Shido's date with Reine is winding down, Reine comes to the realization that history has been rewritten. With DEM approaching, Kurumi arrives at their location to aid Shido.

Kurumi manages to survive Mio's assault and the other Spirits arrive to aid Shido. Realizing why he failed to seal Mio previously, Shido plans to kiss her again and this time make her choose him over Shinji.

While Shido and Mio face each other and convey their feelings, Westcott activates his terrifying ritual. Can Shido and the others stop his plot from achieving fruition?

Driven by her resolve to erase the Spirit of Origin from existence, Kurumi is fighting a battle of her own. And at long last, the identity of Phantom is revealed.

Shido tries to woo Nia whose heart is firmly set on 2D. In order to get Nia to read their manga, the crew challenges her to see who can sell more copies at Comico.

Trapped by Beelzebub in a world of fiction, the crew is desperate to escape. But without their powers to aid them, they're at the mercy of the story they're inside.

Shido and the Spirits decide to visit Tengu City Hot Springs, but they run into some trouble on the way.

Shido encounters the mysterious "Hermit" one rainy day, and Tohka and Origami fight over Shido at school.

Shido wakes up by the troubles of both Tohka and Yoshino and somehow resolves it, meanwhile Origami got suspended for two months by the AST. While eating their breakfast, Shido receives a text from Origami and they discuss about the event that happened a month ago, While cleaning the room of Shido, Tohka notice a suitcase (for their school-trip) that is a resemblance of a drama sequel on the television. Tohka got worried and rushes to find Shido with Origami. While Shido tries to make it up with Tohka by getting her some kinako bread on the way home he notices that the lock of his suitcase was broken, so he went out to meet up with Origami again. While Tohka imagines another scheme of the show she rushes again to find Shido. And this time he caught Shido and Origami together and imagines that Shido is abandoning her for Origami. Tohka gets jealous gaining some of her powers and runs off while carrying Shido's suitcase. Elsewhere, Tohka's unsealed power starts to create a spacequake. Shido rushes to find Tohka and finds her in their special place and Tohka (misunderstanding everything) tries to prevent Shido from leaving but he explains that all is a misunderstanding, while Tohka cannot control her powers and hit Shido with shockwaves but Shido manages to seals Tohka's power again. While Isaac and Ellen are scheming a plan for Tohka, meanwhile Kurumi plots to kill the first spirit.

The suspension placed on Origami is finally lifted, we see Kusakabe having some complaints and a new character is introduced into the series. Shido is selected as the organizer of the Ten-Oh Festival, after a spacequake alarm goes off, Shido gets working and a new spirit is revealed, Diva, proves to be more of a challenge than the other spirits. AST interrupts Diva and they go on trying to take her down resulting in her escaping, after Shido encounters himself in a troublesome situation. The transformation of Shido into Shiori begins. The fierce battle to win Diva over begins, but will Shiori be able to accomplish the task at hand or will Diva be more challenging than expected?

Shido Itsuka is an ordinary high school student living with his little sister in Tengu City, a city that is often disrupted by "spatial quakes". During a spatial quake at the beginning of the school year, he meets a beautiful and mysterious "Spirit".

Shido practices making women fall in love with him and has another encounter with the Spirit "Princess".

Shido goes to Origami's apartment to look for Hermit's puppet, Yoshinon, who was lost during the last fight, and Tohka talks with Reine about her feelings for Shido.

After a very awkward moment in Shido's class where Tohka tries switching genders in an effort to bunk with Shido, the class goes on a field trip to Arubi Island. During the entire trip, Origami and Tohka end up constantly annoying Shido in an effort to win his affections. Meanwhile DEM Industries, an organization with an interest in spirits begins stalking Tohka. Some time later, a massive hurricane appears out of nowhere while Shido and Tohka are on a stroll. Three trash cans strike Tohka, knocking her out in the process while two spirits viciously battle overhead. When Shido tries to intervene, the twin spirits Yuzuru and Kaguya decide that their next battle will be over winning Shido's heart to the latter's dismay. When the two girls follow Shido back to the class holding his arms, Origami becomes enraged over her new competition. As Shido's teacher tries to arrange the girls to be students in the class, Kaguya and Yuzuru explain that they were once one spirit named Yamai and that their contests are in an effort to find out whose personality will stay when the girls fuse and become Yamai once more. Later that day, an incident occurs when the twins drag Shido into the men's bath in an effort to sexually seduce him. Things get worse when Tohka shows up along with the rest of the class.

As the score results for the annual contest comes in, even though Miku won the best performance, the support of Raizen's Maid Café earns Shido enough declare winner. Depress and refusing to accept Shiori's friendship, Miku unleashes her angel Solo brainwashing the crowd, except Tohka, and hold down Shiori. But then Miku finds out Shiori is a guy leading her totally shock. To make matters worse, Fraxinus and Kotori fallen under Miku's control too, and Ellen abducts Tohka. Shido manages to escape, however, he is now a fugitive in the city. Thought-out the disturbance, Shido meets Kurumi and begs her to help him. Tohka awakens in the DEM facility restrained.

Shido encounters a girl named Nia collapsed on the side of the road, but learns there's more to this manga artist than meets the eye.

The girls struggle to sell more than Nia, but they have a few tricks up their sleeves. However, not even the Spirits are safe when Isaac Westcott comes to claim his prize.