AVENGER

Mars has been colonized and is a world where children have been replaced by robot servents known as 'dolls'.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. — Description from AniList community (anilist.co).