Kimi wa petto is a cute story about a girl who one day finds a boy inside a box that is outside her apartment one day. She decides to bring him in and fix his cuts. She then leaves a note for him to eats some food she made then go home because she had to go to work. When she gets home however she finds that he is still there. He tells her that he wants to live there with her like a brother or cousin. In desperation to get him to leave she tells him that if he became her pet then he could stay. And as a pet she says that he would have no rights and do whatever she told him. (not in that perverted way!) To her surprise he agrees and from then on he is known as Momo, her pet.