Koharu Biyori (2001)

Blurb:
Set in the near future where robots are assistants for their human owners, a story unfolds about Takaya and his association with the maid of his dreams. Takaya, an avid collector of dolls, decides to purchase a robot maid named Yui. Yui’s main objective in life is to serve her master, but Takaya treats her like a life-size doll, and is only interested in dressing her up in cute costumes. As the conflicted relationship progresses, we watch as other women enter the picture and try to take Takaya’s affection away from his robot maid.

Source: www.anisearch.com/manga/3445