It is hard to say. The main character (Female) becomes friends with the (Male) character after she is eventually fired for looking for her dog too much and he confesses to having killed her dog. They stay friends and it is insinuated a relationship will begin.
(Though it is never expressly stated) It is hard to argue that the secondary main character (Male) Is not mentally ill and he does violently kill the pets of his neighbors and those around the places he works.