Based On a Visual Novel developed by Minato Soft.

Due to family troubles, Ren Uesugi and his sister, Mihato, leave their home. They end up moving to the city but find themselves with a lack of money. Somehow they are able to find work in the form of the Kuonji family's mansion, being employed as servants to the three sisters of the Kuonji family: Shinra, Miyu, and Yume. Being a servant also associates Ren with the mansion's additional servants and the Kuonji sisters' friends.

(Source: Wikipedia)