When she was sixteen years old, her mother died suddenly, leaving Fang Zi with a study, a letter, a key, and a mysterious man (his mother's secret friend during her lifetime) - Yi Wang.
It was also in that year that Fang Zi learned the secret that his mother had buried for many years, and decided to find his father who belonged to another time and space.
In time after time traveling, she played different roles and experienced different lives; during this period, she experienced joy, pain, expectation, and regret, but she never forgot...