Akari Yoshiyama is graduating high school soon and is expected to lead new life after she passes the university entrance exam, while her mother is working as a pharmacologist. However, her mother has a car accident and the situation is totally changed. She decides to go to 1972 to fullfil her mother's wish.

Kazuko Yoshiyama is a third-year junior-high-school student. One day, while cleaning the lab, she smells lavender and faints. From then on, she has the power to travel through time.