On a world with no women, the surviving men have reinvented females in the form of androids called Marionettes. Normal marionettes are built to serve men and are limited in their actions and emotions until a poor boy named Otaru Mamiya finds a special Saber Marionette named Lime. With war close at hand and two more Saber Marionettes at his side, his life takes a turn for the better as he unlocks the emotions that may hold the key to the salvation of mankind.