The heroine accidentally ate a counterfeit version of APTX4869, so she returned to the first grade of elementary school. However, the heroine will grow one year older every month (so the fake version). Therefore, the heroine Mayaki Yukiko began a miserable life of transferring schools. The God of Creation felt that he owed her, so the heroine traveled through time gorgeously...
Twelve months, twelve grades jumped, leaving very beautiful memories...
Maya Yukiko, you will be strong!