Yoo Jinho, also known in the Japanese version as Kenta Morohishi, is a significant supporting character. He is introduced as a young man from immense wealth, being the second son of the chairman of Yoojin Construction, one of Korea's largest companies. Despite his privileged upbringing, which provides him with access to incredibly rare and expensive high-end gear, Jinho is a D-Rank Hunter with a class specialization as a Tanker. He has a boyish face, gray eyes, and distinctive custard-colored hair that is shaved on the sides.

In terms of personality, Jinho initially comes across as somewhat inexperienced and naive, a "lovable dork" who often serves as a source of comic relief, especially due to his habit of overreacting or misreading situations. His most defining trait, however, is his fierce loyalty and genuine, warm-hearted nature. Despite his high social standing, he never looks down on others and is remarkably pure in a world often marked by greed and betrayal. He is also known for his absurd inability to hold his liquor and a running gag of wearing overly ostentatious, flashy, and expensive armor that is largely impractical.

Jinho’s primary motivation stems from a deep desire to earn the recognition of his powerful father. He initially seeks to prove himself by becoming the Guild Master of the Yoojin Guild, a subsidiary of his family’s construction empire. To achieve this, he needs to complete twenty raids to qualify for the license, a goal that drives him to seek out Sung Jinwoo as a partner. Beyond external validation, he wants to make his own way in the world and not simply rely on his family name.

His role in the story is intrinsically tied to his relationship with Sung Jinwoo. They first meet in a C-Rank dungeon raid party led by the corrupt Hwang Dongsuk. Initially, Jinho, being a D-Rank, offers to protect the E-Rank Jinwoo. However, when the party betrays them and traps them with the dungeon boss, Jinwoo single-handedly saves Jinho’s life. This event completely shifts Jinho’s perception, and he becomes an awestruck and devoted follower, regarding Jinwoo as an older brother figure. Their relationship evolves from a transactional business deal, where Jinho offers Jinwoo a building worth billions of won in exchange for raid help, to a genuine and deep friendship. Jinho becomes Jinwoo’s most trusted lieutenant and the Vice-Guild Master of the Ahjin Guild, focusing on management, administration, and handling the finances and logistics so Jinwoo can focus on combat.

Jinho undergoes a notable personal development arc. He starts as a somewhat sheltered and inexperienced rookie who is initially skeptical of Jinwoo's hidden power. Through their shared dangerous experiences, he gains confidence and sheds some of his initial naivete. By the end of the main story, he abandons his original goal of leading his father’s guild to instead stay loyal to Jinwoo, helping build the Ahjin Guild from the ground up. In the long term, he steps away from the family construction business entirely to follow his own path, founding a successful virtual reality gaming company named Beautiful World or Ahjin Soft. He also eventually marries Sung Jinwoo’s sister, Jin-ah, making his personal connection to Jinwoo a permanent family bond. His abilities as a D-Rank Tanker are modest compared to high-tier hunters, but his endurance and resilience are notable; he was able to withstand torture from the villain Hwang Dongsoo and protect civilians from falling rubble. His true value lies not in combat strength but in his unshakable loyalty, strategic organizational support, and financial resources.