Long Ago

When Link awakens, the first images he sees are of the person he cares for the most in all the world. But that's all: he cannot remember anything, and knows only what the voice in the temple tells him. But before he can even fully understand who he is, he comes across the one in his visions and, alongside her, uncovers his memories from a life since passed. Who is she, and why is Link so sure that he would've given his life to protect her?