Kana and I have been dating since college and are now living together with the intention of getting married. She is cute, kind, and has a nice figure, so I would be extremely happy if we could get married. But before I knew it, she was with that guy! With my best friend, Nitta! Who would have thought that something like that had happened... When does cheating begin? I often hear stories like that, but I thought that although it's different for each person, it's not that different. I thought the same, and so did she. I wanted it to be that way.