Years ago, Kenji Tanaka walked away from it all. As the famed "Oni" of the Ryujin-kai, his name was a legend whispered in equal measure of terror and respect. He sought anonymity in the mundane life of a construction worker, hoping to shield his estranged sister, Yumi, from the darkness that defined him. He believed his past was buried, a story told only by the magnificent, demonic tattoo that covers his back.

He was wrong.

When Goro's brutal Kenpeitai faction launches a war of annihilation against the remnants of the Ryujin-kai, their violence violates a sacred taboo, and Yumi is caught in the crossfire. Her life threatened, her safety shattered, Kenji is dragged back into the life he swore he had left behind. The city is no longer his. The old rules are gone, and Goro's influence has turned every clan, every street corner, into hostile territory.

Framed for a crime he didn't commit and hunted by the very world he once ruled, Kenji becomes a lone ghost in a city that wants him dead. To save his sister from a man who believes in nothing, Kenji must embrace the one thing he fears most: the cold, unstoppable fury of the Oni within. His path is not just one of vengeance, but a desperate, tragic crusade to protect the last innocent part of his life, a journey that will cost him his name, his soul, and what little remains of his humanity.