Qi falls asleep beside her girlfriend Yuanzi and wakes ten years in the past, back in her high school body with memories of their adult life intact. She sees the time shift as a chance to prevent the illness that threatens Yuanzi’s future. At the same time, Qi’s teenage self has awakened in her adult body, leaving two versions of one woman living opposite ends of the same relationship and trying to protect a love neither fully understands from the other’s point of view.