The young boy Togashi Yuta (voiced by Fukuyama Jun) who successfully entered high school was a dark-style chuunibyou patient in junior high school. At that time, he called himself the master of black flames and spent his nonsensical middle school life with a good feeling. But now he "turned over a new leaf" and regarded this experience as a shameful past that he could not bear to look back on. For this reason, he even applied for a high school far away from home where no one knew him. In the new school, Yuta got what he wanted and made friends with slightly normal friends such as Isshiki Makoto (voiced by Hoshi Soichiro), Nibutani Morika (voiced by Akasaki Chinatsu) and senior sister May 7th Fennel (voiced by Asakura Yukimi), and he was also ready to have a romantic relationship with the girl he liked. But what made him scratch his head was that the new resident and classmate upstairs, Kotori Yuki Rika (voiced by Uchida Maaya), was a deep patient of chuunibyou. The little girl was chirping and making weird noises every day. Yuta, who finally got rid of the shadow of junior high school, had a dream of high school love that was becoming increasingly ethereal...