Yeonwoo grapples with the sorrow of his brother's disappearance, only to face the harsh reality of his demise. Gifted a pocket watch, Yeonwoo unravels a grim truth - his brother fell victim to betrayal within the competitive Tower of the Sun God. Armed with his brother's legacy, Yeonwoo, also known as Cain, steps into this treacherous realm. Will he muster the strength and wisdom needed to ascend the tower, vanquishing his brother's foes and overcoming all obstacles in his path?