Miraigata Renai Danshi 46

A girl returns home after a third date with her boyfriend and is greeted by a handsome, unusual boy with large ears who calls her "Mistress." Confused, she learns her older sister has placed a new companion robot prototype, D-46, in her home. The boy is the prototype, appearing like a cute, puppy-like figure. The girl must decide whether to remain faithful to her boyfriend or develop feelings for the android.