Kousuke Kurono sought vengeance after his sister's tragic death following a harrowing assault. Consumed by a thirst for retribution since the young age of 13, he finally achieved his goal after five relentless years. However, the emptiness that followed, having lived solely for vengeance, led him to a desperate act of self-destruction. As he prepared to end his own life with the same blade used in his vendetta, a mysterious voice halted him with a simple question. Awakening in a strange new world, Kousuke found himself far from everything he once knew.