In 2010, Kazuko Yoshiyama (Narumi Yasuda) works as a pharmaceutical researcher secretly developing a formula for time travel. When she is left comatose after a car accident, her daughter Akari learns of her mother's first love, Kazuo Fukamachi (Kanji Ishimaru), from Kazuko's friend Goro Asakura (Masanobu Katsumura). Believing that finding Kazuo will allow her mother to regain consciousness, Akari uses Kazuko's formula to leap back in time to the 1970s in hopes of finding a younger Kazuo. Instead, she meets and befriends Ryota Mizorogi (Nakao Akiyoshi). Together, they attempt to search for Kazuo, but love begins to blossom between Akari and Ryota, despite the fact that Akari must eventually return to the future.