HOLY FUCKIN SHIT!
That's all that I could say for some time after seeing the clip.
The Woman is Hirano Aya 18 she's a voice actress and the voice of the character Suzumiya Haruhi. She dose all her singing and it's all actually her but DAMN her real voice is so different. Above that DAMN her vocal control is through the roof and beyond belief.
Hirano Aya the voice of Haruhi Suzumiya