It's true, they're an odd match. Not exactly what you would expect to find. Their elements are similar, yes, but wind and sea do not mix in nature. Inconceivable as their union seems, it is the strongest ever known to either.
Haruka is the wind. She is both tame and wild, capable of gently brushing the face of a babe or ripping apart buildings and steel towers with a roaring ferocity. She hears the voice of the wind as she runs; none except the fleetest of creatures can keep up when she dashes across the earth. She is the sky, unlimited, stretching across the planet.
Michiru is the sea. She too is capricious, one day lapping gently on the shores and the next rising up in a thirty-foot wave to crash down and destroy everything unfortunate enough to lie in her way. She is riptides and undertows: Calm on the surface but with a deadly trap lying beneath. She flashes and shines in the sun; all manner of creatures rely upon her for sustenance and life—in fact, the world depends on her.
Yet the two are parallels, never meeting or even touching at all. They look upon one another but that is all they are permitted to do. And so it was when Serenity ruled the moon: They could not be together. But now things are different. Now they fight together, live for each other.
Now they are one.