This thesis is an exploration of the relationships between humans and mechanized beings in Japanese science fiction anime. In it I will be discussing the following texts: Ergo Proxy (2006), Chobits (2002), Gunslinger Girl (2003/2004), and Mahoromatic (2001/2002). I argue that these relationships in these anime series take the form of master/slave relationships, with the humans as the masters and the mechanized beings as the slaves. In virtually every case, the mechanized beings are young females and the masters are older human males. I will argue that this dynamic serves to reinforce traditional power structures and gender dynamics in a posthuman landscape. Additionally, I will argue that by enforcing a dynamic of human-male as master and nonhuman-female as slave, science fiction anime works to fortify the “human” as the primary subject of society. This is done to preserve humanism in the overpowering wave of posthumanism.