In "Solo Leveling," the protagonist's growth is significant and captivating throughout the story. Jin-Woo begins as a weak E-rank hunter but gradually becomes one of the strongest hunters due to his determination, hard work, and unique abilities. His evolution showcases not only physical strength but also emotional and mental development as he faces various challenges and adversaries. The growth of the protagonist in "Solo Leveling" is a central element that makes the story engaging and thrilling for readers.