40-year-old Amelia was hit by a bus on her birthday. When she woke up, she suddenly found that it was 2002 and Amelia was 18 years old again, which enabled her to correct all the mistakes she made for the first time. But when she found herself stuck in the "groundhog day" time cycle-waking up every morning on her 18th birthday-she realized that there were still some things to be solved before she could leave the past forever.