Kikaijikake no Marie

Repeated assassination attempts have turned Arthur Louis Zetes into a misanthrope who trusts no human being, so he orders an autonomous robot maid incapable of lying or betraying him. Marie arrives appearing to be the perfect machine: expressionless, efficient, and frighteningly capable, convincing Arthur that he has finally found a servant without human motives.

The problem is that Marie is not a robot at all. She is a highly trained human martial artist pretending to be one because the requested technology does not exist. She must protect Arthur from assassins without exposing herself, even as he begins falling for the “machine” he trusts more than people. The harder Marie tries to act emotionless, the closer Arthur comes to discovering that she has a very real heart.