William, an ordinary student attending an Academy for aspiring hunters, lives a seemingly mundane life until fate intervenes. One day, he stumbles upon the perfect weapon his yoyo. This weapon becomes a pivotal tool that sets William on a path he never could have anticipated.

Tragedy strikes when William's best friend gets injured to a fearsome monster, leaving a profound impact on our protagonist. Which helped him unlocked the system which changed the way his talent grew. In a desperate bid to survive, he ingeniously fashions a string for his yoyo using the spinal cord of a slain monster. This macabre choice reveals the depth of William's commitment, as he harnesses the power of dark steel and other unconventional materials to fashion his formidable weapon.

However, the conflict extends beyond the monstrous adversaries lurking within the dungeons. Guild members, recognizing William's potential, seek to coerce him into joining their ranks. Their influence threatens to disrupt his journey, forcing him to confront the difficult choices that lie ahead.