story idea nr 2:
This takes place in the setting of Mai Otome, an anime series about magical girls, who get their powers from crystals. These girls are forbidden any sexual contact with men, for the sperm kills the nanobots which allows them to be Otome.

Two brothers, about the same age are out playing in the woods. One of them typically male, broad shouldered, edged face. The other softer and smaller. The smaller boys falls through a hole in the ground into a hidden cave. He stumbles around for a second, stings his hand on something as he tries to get up. He's bleeding a little, but not too bad. Upon inspection he finds a dagger he takes with him.

His brother manages to lift him out of the cave. They inspect the dagger to find out it has grooves running from the hilt, carrying some odd darkred liquid along the onyx blade. A large red crystal knob rested on the other end of the silver hilt.

The boy gets sick as unknown to him, the nanobots that were in the red fluid start to multiply and inhibit his body. About two day's later he gets out of bed again. He studies the dagger some more, and two dark red ruby's seemingly fall out of the crystal knob.

No damage to the knob is found, and the boy takes the ruby's to his brother. The brother laughs and says they resemble the otome jewels. He puts one in his ring, presses the other against the boys ear and speaks the words that issue a contract.
the boy, recognising it and playing along, says, 'Materialise!"

To both their complete amazement a Robe appears and the boy becomes an Otome. And just like every other Otome, female. The boy (now girl) is elated, she's finally feeling at peace with herself.

But when the rob disappears he finds himself to be a boy again. The robe will only stay for a short while after brother gives permision. The boygirl needs training, but the only people that offer training to Otome is Garderobe (the name of the training facilities) and they only train girls. So the boy sets off with his brother in search for a way to become female all the time, to solve the mystery of how a boy became an Otome and to avoid being misused by the many scheming masters, otome, princes and other royalties.