うちの清楚系委員長がかつて中二病アイドルだったことを俺だけが知っている。

A chuunibyou girl who once called her herself the "Nightmare Disaster" — also known as Mea. She was once Kurusu Reiou's troublemaking friend. They spent precious time together, taking pictures of her, uploading them to social media and making them go viral, even though Rei didn't even know her real name. This continued until Mea was scouted by an agency and left their hometown. Eventually, Mea made her entertainment industry debut as a chuunibyou idol. However, after Reiou entered high school, he discovered that the class president, Juunaya Nagi, was none other than Mea, who had graduated from her chuunibyou phase. For some reason, she desperately wanted to become the student council president as a first-year student. But the current Nagi had become a socially awkward, introverted girl. In order to help Nagi run for student council president, Reiou must once again become her supporting producer...!?