Yojiro Akizuki, the Eternal Assassin, is a 17-year-old mercenary bound to obliterate the supernatural Head of the Conqueror with his Moon Tear Sword—a blade whose hilt ornaments pulse in the artifact’s proximity, igniting an eerie glow in his eyes. His crusade stems from guilt over failing to shield Ryoma Sakamoto, the progressive samurai he once guarded and cherished, whose assassination during the Bakumatsu era’s upheaval anchors his resolve. Roaming a Japan fractured by political strife, he crosses paths with the Yuyama Troupe, a kabuki ensemble thirsting to avenge their leader Kakunojo’s slain parents.

Though their alliance begins as transactional, Yojiro uncovers a shared past with Kakunojo: both were raised in the same orphanage, their fates now knotted as tightly as their blades. Her sword, the “yang” to his Moon Tear’s “yin,” mirrors their fragile bond, strained by his stoic fixation on duty. Yet beneath his detached exterior linger unspoken affections, often eclipsed by the cursed relic’s call.

The Head of the Conqueror, a catalyst for centuries of chaos, defies destruction even when shattered, compelling Yojiro into an endless cycle of pursuit. His journey weaves through clashing factions and fragile alliances, each step shadowed by the ghost of Ryoma and the toll of immortality. Torn between the solitary weight of his destiny and fleeting glimpses of kinship, he walks a path where supernatural forces twist history—and where redemption may lie just beyond the edge of his blade.