Con La Hierba De Almohada by Lian Hearn

In the aftermath of upheaval, a young warrior trained in forbidden arts and the fiercely independent noblewoman he loves are drawn into a fragile, treacherous peace where secret loyalties, rival warlords and a shadowy assassin clan force them to choose between duty, survival and revenge; as political plots and personal betrayals mount, they must navigate love, vengeance and the costs of power in a vividly realized feudal world.