This is the theme for one of the central characters to the story, Kiryl Hemanna. While I don't want to elaborate very much on her role, or what she has to do with the story, I will say that the player will see a lot of her. We'll go with that for now.
Either way, her theme is made up of two parts mystery, three parts love, and two parts ancient nobility. This song is also my most blatant homage to my favorite composer, Yasunori Mitsuda. There's little bits of inspiration from his various works all over this darn song.
A careful listener will pick up a very blatant connection between this song and a couple of other character's themes. I'd prefer to let that musical spoiler speak for itself. :3