I'm a humble businessman who is annoyed by my wife and children. Today is my birthday, but my family left me behind to go on a trip. I wanted someone to celebrate with me, even though I'm just an old man. So I called a delivery health service for the first time in my life. That's where I met Rin. I wondered why such a cute girl was working in the sex industry... Before I knew it, I was thinking about her all the time... and I fell in love despite my age.