A second-year student at Minegahara High School.
He's currently dating his senpai, popular actress Mai Sakurajima. In order to get into the same university as Mai, he studies hard for the entrance exams.
A third-year student at Minegahara High School.
Previously busy with her work as an actress, Mai was not used to life as a student and thus was treated like the wind, an invisible force somewhere. Due to this treatment, she developed Adolescence Syndrome and was no longer visible to those around her. With the help of Sakuta, Mai was able to fix this problem, go back to work as an actress, and study for her university entrance exams. She's quite busy day to day.
Sakuta's little sister.
Kaede developed a case of Adolescence Syndrome that scarred her body as she suffered mental anguish from online bullying at the previous middle school she attended. The bullying caused her mental stress and memory loss. Two years after that, she developed a different personality known as "Kaede," who never left the house. Even after her memory returned, "Kaede" has taken over her endeavors and now she's working hard on going back to school like everyone else. With middle school graduation coming up soon, she worries about her future going forward.
A first-year student at Minegahara High School.
Tomoe was always kicking each other's butts with her friend and senpai, Sakuta. After being confessed to by the senpai her friend admires, she developed Adolescence Syndrome that repeated the same day. Always filled with new topics, Tomoe is now on good terms with Sakuta as senpai and kouhai. She also works part-time with Sakuta at a family restaurant.
A second-year student at Minegahara High School who's a part of the science club. She's one of Sakuta's few friends. Sakuta always goes to her for advice about cases of Adolescence Syndrome he encounters. She gives him her advice all the meanwhile looking pretty discontent while doing so. Suffering from loneliness, she has hurt herself using social media in the past and has experienced Adolescence Syndrome where two contradicting sides of her existed.
Nodoka is Mai's younger-half sister from a different mother who's part of the idol group, Sweet Bullet. Compared to Mai since she was a young child, she developed an inferiority complex that caused her to develop Adolescence Syndrome in which she switches bodies with Mai. Everyone knows she's attached to her older sister and she keeps Sakuta in check so that he doesn't do anything bad to Mai. Nodoka gets along with Kaede and Mai dotes on her.
Uzuki is the leader of the Sweet Bullet group that Nodoka's a member of. Her fans lovingly call her "Zukki."
Always doing things on her own time and down-to-earth, she often surprises those around her with unexpected words and actions. For better or worse, she can't read the air and acts very close to even people she's just met. Normally hyper, she has a cheerful personality.