Yeon-woo Kim sat in his small room, surrounded by faded posters of famous rankers. Each poster was a testament to his dreams, dreams that now seemed so far out of reach. At 15 years old, Yeon-woo had always dreamed of becoming the strongest ranker, admired and respected by all.

But fate had other plans.

Yeon-woo's awakening had shattered his dreams. When the day came for him to receive his rank, he had brimmed with excitement, eagerly awaiting the moment he would join the ranks of the elite. However, as the results came in, his excitement turned to disbelief, then to despair.

An F class useless rank.

The words echoed in his mind, a cruel reminder of his inadequacy. How could he, with dreams of greatness, be labeled as useless? It felt like a slap to the face, a rejection of everything he had hoped to achieve.

Yeon-woo's family had always struggled to make ends meet. His father, Hyun-joon Kim, had worked tirelessly as a laborer, his hands calloused from years of hard work. His mother, Soo-jin Kim, had been a loving homemaker, her warm smile brightening even the darkest days.

But tragedy had struck when Yeon-woo was just 10 years old. A monster outbreak had ravaged their town, leaving chaos and devastation in its wake. Yeon-woo's father had been one of the unlucky ones, torn from his family by the merciless claws of a monstrous creature.

The loss had shattered their family, leaving them broken and struggling to survive. Yeon-woo had vowed to protect his mother and younger sister, Ji-soo, but fate had other plans. Just one year later, another outbreak had claimed his mother's life, leaving Ji-soo paralyzed with grief and shock.

Since then, Yeon-woo had dedicated his life to caring for Ji-soo, sacrificing his own dreams for the sake of his family. He took on odd jobs and menial tasks, doing whatever it took to put food on the table and keep a roof over their heads. But no matter how hard he worked, it was never enough.

As Ji-soo rolled into his room in her wheelchair, her eyes filled with concern, Yeon-woo forced a smile. "Cheer up, Yeon-woo! You'll find your calling someday," she said softly, her voice tinged with sadness.

But Yeon-woo couldn't bring himself to believe her words. How could he find his calling when his dreams lay shattered at his feet?

Twist: Just as Yeon-woo sinks into despair, a mysterious letter arrives, inviting him to a B class dungeon expedition. Could this be the opportunity he's been waiting for, or is it just another cruel twist of fate?