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".

With the support of Ratatoskr, Shido goes on a date with Tohka as Origami watches from afar.

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

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

Shido takes Tohka, Kurumi, and Origami out on dates on the same day. Will he be found out?

Shido and Kotori enjoy their date at the amusement park until they are interrupted by Origami.

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.

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.

The twin spirits, still trying to seduce Shido, start cuddling up to Shido completely naked in bed. The situation worsens when one of his teachers walks in on the mess. Later, Shido plans to seal the Yamai twins' powers without letting one of them win in an effort to avoid both the unpredictability of the loser and what would happen to the loser's personality. During their contest, they have Shido coat their backs in suntan lotion ending up turned on from the application. Later, the Yamai sisters team up with Shido to take on Tohka and Origami in a volleyball game in which the winner is the former's team. During the afternoon, Origami is ambushed by a strange mech-like being.

The woman stalking Tohka and Shido before, Ellen, finally reveals her true colors and orders a pack of mechs called Bandersnatch units after Tohka in an attempt to capture her. During the clash, Tohka gets incapacitated and captured only for Shido to call upon her sword to break the Bandersnatch off her. Meanwhile, Kannazuki and his crew on board the Fraxinus gets attacked by an enemy airship. Kannazuki launches a counterattack after deflecting several shots, leading to a full-scale dogfight between the two ships. Back at Shido's battle, Ellen falls down into a pit trap (oddly enough) dug by Ai, Mai, and Mii allowing Shido and Tohka to escape. Running to Kaguya and Yuzuru, he summons Tohka's power to intervene the duel and convinces both the girls to forget about becoming Yamai and focus on enjoying their lives together. Noticing the airship that attacked the Fraxinus, the twins combine their powers and eviscerate the ship with one massive blast. After the incident, Shido successfully seals the Yamai twins' powers, unfortunately stripping them of their clothes just as Tohka arrives. Meanwhile, Kotori learns from a strange man that Shido has manifested a spirit's power and that she might have to kill Shido if the situation worsens.