Mars has been colonized and is a world where children have been replaced by robot servants known as "dolls." Layla is a skilled fighter with a tragic past who travels about the world. Her companions are Nei, a strange and unique doll with some unknown ties to Layla, and Speedy, who is a doll breeder. The founders of Mars see the trio as a threat to their world, and each time they attack Layla and Nei a bit more of their mysterious past and future is revealed. (myanimelist.net)