Across the Nightingale Floor by Lian Hearn

In a land of warlords and assassins inspired by feudal Japan, a young man named Takeo is saved from massacre by the mysterious Lord Otori. Taken under his wing, Takeo discovers he possesses extraordinary abilities — the hearing of a god, the stealth of a shadow, and a destiny entwined with vengeance. As he trains to master the deadly arts of the Tribe, he must navigate treachery, loyalty, and forbidden love. When his path crosses with the beautiful Kaede, both are drawn into a web of power that will change their world forever. Across the Nightingale Floor is a tale of honor, betrayal, and fate — a hauntingly beautiful beginning to the Tales of the Otori series.