In their previous lives, Lei Zhan died during the final mission to eliminate Black Cat. Ye Cunxin clutched his body beneath the military flag and wept, never marrying. As they lay dying, the two promised to find each other in their next lives. By chance, they were both reborn and returned to the beginning of the Fire Phoenix selection.
In this life, they both carry memories of their previous lives and a love etched into their bones. On the surface, they are a strict instructor and a rebellious female recruit; in secret, they are soulmates who would die for each other. Lei Zhan does everything he can to restrain his desire to protect her, afraid to cross the line set by military regulations. Ye Cunxin keeps her knowledge of the future hidden, tempering her sharp edges as she steadily grows stronger. He treats everyone equally on the surface, but deep down, his love for her is absolute.
Key changes
They only confess their feelings in private after the Fire Phoenix unit is formally established and Ye Cunxin is no longer a trainee, avoiding the major problem of an instructor dating a student while strictly observing military discipline.
During a holiday visit home, Ye Cunxin takes the initiative to confront her mother, Zhang Haiyan, in depth. Zhang Haiyan’s inner turmoil is developed layer by layer, and Ye persuades her to turn herself in and become a double agent for the police. In the end, Zhang Haiyan’s name is cleared, and mother and daughter reunite safely.
It's very beautiful. I recommend you to watch it.