掌を返す

Idiom

 * 1) to flip-flop; to do an about-face; to flip over one's hand

Etymology 2
Compare Chinese

Idiom

 * 1) to do something easy as turning one's hand over
 * 2) to flip-flop; to do an about-face; to flip over one's hand
 * 1) to flip-flop; to do an about-face; to flip over one's hand