Ai-chan for Me ~Maid Choukyou Hen~

Hero receives a letter from his friend inviting him to apply for a job in a mansion. There he meets three newly employed maids and chooses one of them to take care of his needs as man. The next day he is tasked by the mansion owner to train the same maid and he takes the job since he cares for the girl. Each girl has mental shackles and it depends on the main character whether the shackles are to be lifted or tightened.

[From vndbreview]