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.

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.

Mirei steals Chifuyu's ability when she uses it to protect Hatoko, before Tomoyo helps everyone to escape. Regrouping at a karaoke box, the group deduce that the Mirei they fought against was an imposter possessing her body. Jurai goes by himself to confront the imposter, tricking her into stealing his enhanced "Dark and Dark of the End", which only serves to burn its user's hand with a neverending flame that cannot be extinguished. This forces the imposter to return Mirei to her body, after which they use Chifuyu's powers to chop off the burning hands and send them to another dimension whilst Sayumi heals them. Following the incident, Tomoyo and Hatoko discuss their respective feelings for Jurai, before everyone returns to their everyday lives.