A 'Knight' with you

The story is about a girl who was living in present time and a boy who was living all this time since the period stated at the history books. One having no memories at all and one having all the guilt and sadness. How will they face the reality when time was a huge obstacle between them? How will they solve mysteries full of uncertainty and lies? Will the girl still accept the truth? Or will the boy still lie to her to protect her? After all, their love is the only thing being unchanged.