3X3 Eyes follows the tale of Yakumo Fuuji, a young man who, after a peculiar turn of events, becomes bound as the eternal servant of the final surviving member of a race of immortal beings with three eyes. To preserve his life, the immortal fuses with his essence, granting him immortality as well. Their intertwined fates set them on a quest to seek a method to restore his humanity. Yet, their journey is rife with challenges, especially considering the immortal possesses a dual nature - one charmingly sweet and the other fiercely destructive. Amidst these complexities, intricate relationships blossom between them.