Josh decided to look at the pages on 'sex', as you might expect from a perv like him. It talked about two distinct meanings of the word, sex as in sexual activity and sex as in sexual characteristics. The definition was very complex and detailed what the sexual parts of male and female humans looked like, as well as noting how these sex characteristics were not the case in all humans due to unorthodox chromosomal makeup and were distinct from gender. After the gender part, one sentence intrigued Josh: 'Despite this, humans' sexes are determined at birth and while transitioning can affirm a person's gender and adjust their sex characteristics, it cannot change their chromosomal makeup.'
Josh thought about this for a moment and realized he'd like to rewrite this. He had questioned his gender sometimes, but hadn't felt he could go through with it considering how expensive and imperfect transitioning was and how he knew a lot of people didn't understand it. He reasoned it'd be nice to change things so it was possible for people to change sex at will.
Once he got home, he raced up to his bedroom, got some Wite-Out from his drawer, brushed it over the sentence and the part before, and rewrote it. Once he was finished, it said: 'Human's sexes are determined at birth, but their gender is distinct from sex, and once they reach puberty humans become hermaphrodites, meaning they are able to change their sex at will to affirm their preferred gender or find a mate.'
Now to test if this had worked. Josh locked his door, undressed and stood in front of the mirror. He focused on the idea of turning into a girl, and instead of feeling like something that couldn't be done it felt more like focusing on something funny to make yourself laugh, sad to make yourself cry, or something arousing to make yourself horny- it took a bit of effort, but the body would respond to it as an emotional need.
Sure enough, Josh watched in amazement as his body started changing sex. His body hair receded almost everywhere and his skin seemed to turn more soft and smooth. He shrank and slimmed in many places, his figure developing soft curves as it pushed inward, and his arms and legs and hands and feet seeming more small and lithe. His shoulders narrowed and his hips pushed outwards, his neck and larynx shrank and his facial features subtly reconstituted from boyish to girlish. An indescribable warmth emerged in his chest, and his nipples became intensely sensitive as he felt them growing. Under them, flesh sprouted as soft breasts sprouted from a previously flat chest. Once they had finished forming, the odd sensations moved to his crotch, and before his eyes his penis started to recede away while one by one his testicles slid back inside him- or rather, her. Now the last of Josh's masculinity was fading, 'he' felt like an inaccurate way to describe herself. Soon she had formed a vaginal slit where his scrotum had been and his penis had receded into her clitoris.
Josie, as she realized was her name as a girl, looked at herself and smiled. She'd made a massive change for the better in reality, and wondered what to do next...