Arsenal Military Academy.

In 1910s China, nineteen year old Xie Xiang follows in her deceased brother's footsteps and enrolls in military school disguised as a man. She befriends her fellow cadets and and earns the respect of her instructors during the intense training. However, when the unfortunate arrival of the Imperial Japanese troops creates a web of distressing conspiracies, the batch and their allies are forced to prove their courage and resilience.