Tonari ni Sunderu Jirai Joshi ni Seikatsu o Midasarete Komaru The Motion Anime

The main character of the story came home after a hard day's work. A pretty and very drunk girl was waiting for him on the doorstep. She said that she had lost her keys and asked him to help her. Since that day she began to drink at the hero's house every day and have sex with him....