Among the three Rasho, the generals who rule the land of the Asuras, only Hyo hangs on to a shred of his humanity. Deceived into believing that Kenshiro is responsible for the death of his sister, Hyo enters the demon realm to confront him. Meanwhile, Kenshiro searches for Hokuto Shinken's ultimate secret technique, one he will need when he squares off against the demon lord Kaio once again. What fuels Kaio's hatred, and what secret does he hold that could change Kenshiro's fate?