We were three childhood friends who had been friends since elementary school. I confessed to one of them, Kei-kun, that I was dating, but I had never dated anyone else before, and to be honest, I didn't know how good sex was. Of course, I didn't know anything other than Kei-kun. But,,, I discovered that my vulva had spread out behind my navel, and every time my uterus was hit by that punch, I would go crazy with climax.