I had been in a relationship with my son for some time, but that wasn't enough for me, so I started having a relationship with my best friend Ryoko's son as well. I later learned that it was the same with Ryoko, and before I knew it, she had also started a relationship with my son. What's more, Ryoko and I weren't just best friends, we were in a lesbian relationship. One day, my sons found out about it. And so the four of us developed into a forbidden mother-child swap.