Vesper is fighting an army of alien invaders by using powerful androids. Mahoro is Vesper's most powerful android but she does not have much operating time left and will stop working. If she conserves power, she will prolong her life by a year. She is given the chance to live a normal life and she chooses to become a maid for a high school student who lives all by himself.
A teenager named Suguru Misato decides to hire a maid to help him with the house since his parents have passed away. He hires a former combat android named Mahoro as his maid.
Suguru has returned to school and has to explain to all his friends why he now has packed lunches and ironed clothing. His teacher dislikes Mahoro, as she feels like Mahoro is a threat to her.
Mahoro's and Ms. Shikijo rivalry for Suguru's attention comes to a peak while they are all visiting a bathhouse. The next day Suguru asks Mahoro to go to the cemetery with him to mark the anniversary of his Father's death.
Everyone goes to the beach. Things get crazy when an android shows up and rips the swimsuits off all the girls. This makes Mahoro return to her combat mode to correction this situation.
During a staff meeting a letter is read aloud that Mahoro wrote describing her life as a maid.
Another android joins Mahoro, as Vespers thinks Mahoro is in danger since she has been stripped of most of her combat capabilities. Mahoro has also been chosen to perform in the Summer Festival.
As everyone is returning to school after the summer vacation, Chizuko is nearly run over by a car that is out of control. Later that day the substitute teacher turns out to be the driver of that car. Mahoro is attacked that afternoon by a combat android that wants to destroy her.
Suguru throws a party in order to try and figure out the connection between Mahoro and the new substitute teacher. Mahoro is starting to realize that she wants a home and wants to take care of people.
The final dual has been set for Mahoro and Tou Ryuga so she asks Suguru out for a date. During the date Mahoro tells Suguru about Rou Ryuga.
This is a flashback episode explaining Mahoro's training and battle skills.
Mahoro and Tou Ryuga face off in battle. Mahoro quickly realizes that she will have to use drastic actions in order to survive.
Mahoro's thoughts before she blacks out are of Suguru and returning before he wakes up and finds her note. Mahoro wants nothing more than to continue her life back home with Suguru.