Natsuki, who lives with her father, has been a beautiful girl since childhood, and her neighbor Fujita has had an evil love for her. Her father trusted Fujita, but Natsuki deeply disliked the man who sometimes looked at her with naughty eyes. At that time, her father has to go on a business trip for her work. Taking this opportunity, Fujita tries to somehow make Natsuki his thing by using the ``Happiness App'' he got from her... Now you're the only one with me