>>537875592
Meet the INTESTINE-CHAN
While around her dad's house construction site she slipped and fall onto somewhat protruding concrete's reinforcing bars resulting in body puncture in her lower abdomen. The first penetration was where lower intestine twists and bends. Initial infection left the affected stretch of intestine overreacting resulting in constant brown alarms, thus the only solution was another surgery that rerouted the healthy part of the intestine through the stomach to external fecal matter collection bag. The first deeper and second shallower puncture penetrated where her ovaries were, thus leaving her permanently infertile.
She would arrive at Yamaku near simultaneously with Hisao, and after they meet and judge each other to be the safe ground, they become the ersatz normal* (*healthy at first glance) friends they both used to have. I'm thinking plot would progress around her feeding Hisao lies about her "eating disorder" being nothing but genetic lottery because she doesn't feel like breaking the facade. That's until she reaches the point where she feels she can't lie anymore to somebody she's considers a friend. She may also join/create the swimming club, but I'm not sure weather that's fitting place for them to hang around.
Her arc overall would revolve around dissolving the taboo she'd built around her injury (unlike other girls it's intimate area of body) and acknowledging & accepting the change that is both acquired and recent, as opposed to predetermined or previously accepted. This is kinda "the problem must be in your pants" route that we never got that's also gender swapped. While I can still see her being able to be sexually active, in a healthy way of course. I don't think she would want that to happen as she will be withdrawn* (*asexual?) in these matters. So if any segz scenes were to happen they would be minimal exposure; Trousers pulled slightly down and panties to the side, as to hide the shit bag and post surgery scarring.