Puberty Syndrome is a rare, supernatural condition affecting teenagers, yet many dismiss it as a myth. High school student Sakuta Azusagawa knows it's real, as he encounters its effects firsthand. Mai Sakurajima, a former child actress, now attends his school after mysteriously quitting her career. One day, Sakuta spots her in a bunny girl costume, yet no one else acknowledges her presence. He learns that Mai is another victim of Puberty Syndrome. As Sakuta helps her, he discovers more girls in his school suffering from this strange affliction, leading to deepening connections and new challenges.