When the world started, there was nothing but the Sky and Land. They intertwined perfectly- where ever one went, the other was there. They were never apart.
Then came Separation. Sky and Land craved her, and all the beautiful things she betowed upon them. Land suddenly had plants and Sky had stars. They wanted Separation more than they appreciated eachother as the days flew by. They soon began to forget eachother's friendship, viewing it as only competition for Separation's love.
But then Separation gave Sky the largest star of all, a Sun, and gave Land large bodies of water. And as the day set between them, and the Sky's sun fell and the Land's water glistened, they realized how far their infatuation had torn them apart. They realized that no matter how far they reached, they could never touch again.
Only at the farthest point of the globe will it seem as though the Sky is finally touching the Land again, but even then it is nothing but an illusion.
For Land and Sky had lost themselves in Separation, and now Separation would forever be between them.
...
Have you ever translated the character's names?
Sora, Sky.
Riku, Land.
Kairi, Separation.