Maid Neko-san wa Ikaga Desu ka? ~Kikaijikake no Koi Monogatari~

One day during college 's summer vacation main character receives a huge baggage sent from his father. Inside is a a humanoid robot Ren with cat ears and a tail. It turns out she is constructed by hero's father and is sent for testing during 40 days. Despite being produced to handle maid duties, Ren has a lot of failures. But hero gets attached to her anyway.

[From vndbreview]