Kimi wa Meido-sama.

A High school student, Hitoyoshi Yokoya lives alone in his house and has no one to take care of him. One day a miracle happens and he sees a girl with a very attractive personality in a maid dress ringing his doorbell. When he talks to her she wants to be his maid but he refuses because she is just a stranger. On that day she saved him from an accident and after that he let her be his maid. Later he came to know that she was an assassin who wanted to change her life. She doesn’t have a clue about ordinary life. She was learning new things that made her feel happier and in this way, she discovered real happiness.