Author's note: This story is basically a dream that I made some times ago and that I wanted to share.
I know it's short, sorry, I'll do better the next time :)
Thanks to my friend Leebot for beta-reading.
On a planet far far away lived a quite futuristic human society. People were all wearing white clothes, cities were clean, modern and spacious although there wasn't a lot of vegetation.
Humans in this world had a distinctive feature: before they reached the age of 16 it was impossible to know a child's gender. No clue, no biological sign could tell if a child would become a boy or a girl (don't ask how they urinate, that's private). The language in this society admitted a neutral gender that was used to designate children (like a singular version of "they" in English).
In this strange world lived two children, Natsuki and Shizuru. Shizuru was a calm and smart child, with long chestnut hair whose bangs didn't hide their bewitching crimson eyes. Natsuki was a lively child with long blue hair and beautiful emerald eyes. (Of course the hair length was not a clue, children were free to choose their hair style).
They were quite opposite: Shizuru was always smiling and amiable, Natsuki was often grumpy. Shizuru was an obedient and good student, Natsuki didn't stand authority and often missed school. But despite that (or maybe thanks to that) they loved each other. It didn't seem to bother anyone; the grown-ups didn't pay attention to children's passing romances. Maybe they thought it was a deep friendship or a sort of brotherly love. But it was not a crush, their love was pure and sincere.
Each of them was sure of becoming a man whereas the other would become a woman. Natsuki thought that the natural charm that enveloped Shizuru like a halo, their calm temperament and their good manners were obvious clues of their future femininity, whereas themself, vulgar and bad-tempered, had the behaviour of a young, scrapper boy.
As for Shizuru, their only desire was to protect their dear Natsuki, who, despite their swaggering, hid a very sensible, caring and sweet side as well as a huge need to be loved. The chestnut-haired child was the shoulder on which their loved one could rest, the shield behind which Natsuki could be safe. Shizuru thought that their protective side was a clue of their future role of a strong man.
Puberty arose and both children proved to be girls. It didn't change anything to their feelings, their love was far beyond that. However, society didn't look favourably on such a relationship. It was commonly admitted that a woman should be with a man, that it was the order of things.
Luckily for the two lovers, it wasn't in the mores to be violent, whatever the reason. In a society where everybody had the same skin colour, similar clothes, close tastes, differences weren't frequent, but their fellows behaviour contented themselves with surprise, lack of understanding, sometimes amusement or denial that such a kind of love could exist.
But the girls never suffered from violence or scorn from their fellow citizens.
What's more, over time they became more and more accepted, recognised. Their love was so pure, so sincere! And it lasted for so long! Thus nobody could doubt of their feelings anymore.
Love always wins!