Chinese sisters sparring in bamboo forest during wartime

The Chinese sisterhood in 2nd sino-japanese war. 1944. A chinese woman soldier in communist khaki army uniform older sister (pic 1) and a chinese woman soldier in nationalist light blue army uniform little sister (Pic 2) with their tai chi shoes have straps (Pic 3) that fighting each other during the practice their martial art with hand-to-hand combat sparring by punching and kicking at the bamboo jungle. Their smile in their lips is peaceful. They are only twenty years old. Her older sister (pic 1) that use her front kick to kicking on her stomach and make her pain.