The members of Senkō High School's literature club become shocked when Jurai Andou, a boy usually known for his 'chunibyo' delusions, suddenly develops superpowers of his own. Six months later, each of the club members have since developed their own superpowers, which they put to the test in their monthly check-up. When student council member Mirei Kudou comes to check on the club, she ends up misinterpreting Jurai's chunibyo behavior and inadvertently reveals that she herself has developed superpowers as well. Mirei challenges the club to a superpower battle, using her own ability to steal Jurai's "Dark and Dark" ability, only to find it to be nothing more than a useless lukewarm flame. With the other members knowing not to show off their powers before her, Sayumi easily beat Mirei in a physical match. Learning that Mirei learned of the club's powers from an anonymous text, the group become curious about just who sent it.

The literature club have a recreation day spent playing tennis with their abilities. Later, as Jurai goes off to search for his misplaced "Bloody Bible", the other girls reflect on how he, despite his odd behavior, has been helping them all this time. While retrieving his book, Jurai comes across an alumnus named Hajime Kiryuu, who seems to share his passion for chunibyo naming. He is later revealed to be Tomoyo's older half-brother who left home a year ago. The next day, honorary literature club member Chifuyu Himeki appears before Jurai, stating she has quit elementary school.

After working with the Literature Club members to make a personalized video game for Jurai's birthday, Sayumi Takanashi, who has the power to revert things to their original state, catches a cold. Jurai pays Sayumi a visit at her house, where he meets her younger sister Maiya, though Sayumi attitude suddenly changes when Jurai bring up how she was the student council in middle school. The next day, after Jurai hears from Maiya about how Sayumi had originally wanted to join the student council during high school, Mirei theorizes she may have turned it down due to her powers. This leads Jurai to recall an incident that happened ten months ago in which Sayumi, who suggested they use her "Root of Origin" ability to remove everyone's powers, battled against Jurai who was against it. The result of that battle showed that Sayumi's power could not erase Jurai's Dark and Dark, as their powers were meant to be accepted as part of themselves.

Hatoko is invited to Jurai's house to make dinner for him and his sister, but gets downhearted when Jurai decides to stay at school to talk with Tomoyo about her writing. Hatoko gets angry at Jurai when he refuses to tell her what he talked about with Tomoyo and snaps at him, going on a rant about how she just can't understand his chunibyo behavior before running off. As Jurai goes off in search for Hatoko, he worries that he might have been putting stress on her the entire time, but Tomoyo slaps some sense into him and helps him search. Meanwhile, Hatoko comes across another Chunibyo, who teaches her not to worry about not being able to understand chunibyo, before using his own power to knock Hatoko unconscious. With Jurai having no luck in finding Hatoko, Sayumi decides to bring her Root of Origin to the next stage in order to find her.

While asking Jurai for some feedback on her completed novel, Tomoyo becomes embarrassed when she hears about a certain silver-wigged girl who convinced Jurai to continue his chunibyo lifestyle. Later, after the girls make Jurai to promise never to use his awakened power ever again, Hatoko helps Tomoyo with her studies. The next day, Jurai makes a promise with Chifuyu to take her to the pool during summer break, with Chifuyu learning that she may have developed feelings for him, while another male classmate, Shizumu Sagami, approaches Sayumi with the prospect of getting together with Jurai. Meanwhile, Hatoko reveals to Tomoyo that she is in love with Jurai, asking if she also feels the same.

Tomoyo recalls how she first met Jurai during her chunibyo days. Meanwhile, Hatoko tries to follow a magazine's advice to get Jurai to fall for her during their vacation, though not too much success. Upon his return, Jurai invites Tomoyo to a summer festival where they talk things out and watch the fireworks together, leading Tomoyo to realise she is also in love with Jurai. The next day, Mirei, who was captured by Naoe Hagiura the previous night, summons the literature club members together and steals Hatoko's ability, using it against her.