I always love his stories. Obviously, they're perfectly fine for fapping to, but the stories themselves seem like they have some thought put into them and not just merely smut.
The clear-haired (purple?) senpai is going through the procedure for something called "Final Gender Decision". Between the ages 13-18, people can change their sex freely with the help of medicine. Dude asks senpai to model for him. Senpai has first menstruation come up so s/he goes for surgery to remove his/her penis. Fast forward a year and they meet again. Senpai's been busy learning how to integrate seamlessly into society as a female. Lead up to sex is to test out whether sex works (just a cover?). Last page and they're dating a few days later. School uniform is from the school they were attending when senpai disappeared.
Yes, I have issues trying to decide which gender pronouns to use. Whatever.