Former idol Touko Minayoshi retired at the peak of her popularity, going down as a legend in the world of show business. Years later, she is living a normal life as a happily married wife with a son named Yuu. But one day, returning home from school, Yuu discovers that his mother has transformed into a strange creature, and despite his best efforts, he is unable to figure out the reason.

Years pass, and the threat of Touko's situation being exposed appears. Now, the teenaged Yuu finds himself sent back in time to before his mother debuted as an idol. Recognizing this to be an opportunity to set things right, Yuu embarks on a journey to bring his mother back to her original form!