Help finding a fiting song

[iNSPIR1T]

Does anyone know of a fitting song? I've been dying to make a Yosuga no Sora video, however I'm very unfamiliar with music. Technically there isn't a song that can match Haru and Sora's relationship's complexity, but I'm sure I'll find something.

Even if you don't know the anime, I'm sure something along the lines of a song about Unrequited Love may work. That's really the best I can do in terms of categorizing a type of song that may work. However, even that seems off. Or perhaps a very bitter love song.

I'm looking for a song that isn't super mainstream. Any assistance would be most appreciated.

[Shin-AMV]

I haven't seen the anime, but I think about this song for unrequited love. Not really bitter, but a strong sense of loss goes throughout. I don't think its super mainstream either, so hope it helps.

Boats and Birds - Gregory and the Hawk
http://www.youtube.com/watch?v=r8W13ldm1Jo

[iNSPIR1T]

The song may or may not work. Its a bit far from their relationship, but could been pulled off (possibly), either way, it was a nice song that I could probably use for other anime regardless of if it works out for the one I'm working on.

Thank you for your suggestion.