My name is Makoto. I met my girlfriend Momo-chan in the tennis club at the same university and we've been dating ever since. Her older sister Mio chan is also a fourth-year student at the same university, studying law. She's beautiful, intelligent, and a great cook. I thought she was a really wonderful woman. The other day, when I went to visit her at her house, her older sister suddenly said to me, without her younger sister noticing: "You know... I want you to call me 'slut', Makoto-san..."