Mahoro is an android created by VESPER to fight an alien invasion. Being an android, she has a limited life span, she only has 398 days to live, and is given the choice to do anything she wants or keep fighting for them. She chooses to become a maid for Suguru Misato, because she still feel responsible for killing her superior commander Suguru's father.
Mahoro has a very sunny disposition and is friendly to just about everyone. She is however, extremely hostile towards anything perverted, she will take the any dirty magazines she find and hide them somewhere. She is very concerned about her appearance, often not allowing herself to wear normal clothes as she is concerned that it would look bad to the neighbors given her position as a maid. She is also obsessed with her small breasts often asking VESPER to enlarge them.