It is a long road to becoming a maid so there is an academy dedicated to it. It is part of the curriculum to train somewhere and have a close relationship with their master. It is there that the girls fulfill their dreams to become fully elegant maids.

Akito accepts a contract where four below-average maids in training will come to live with him. These "leftover and unwanted" maids will be able to graduate all together as long as their master awards them approval.

And so Akito and the maids' first rough year together begins...

[from MyAnimeList]