Knob-yan, whose full name is Nobuo Muroya, is a supporting character in the Gantz storyline. He is a veteran and a prominent member of the Osaka team, a group of participants distinguished by their extensive experience and advanced combat capabilities within the Gantz game. Muroya has successfully cleared the game four times, an achievement that establishes him as one of the most seasoned players in the narrative. This track record naturally positions him as a leader within the Osaka team, where he fights closely alongside his teammates Shimaki and Kuwabara, often coordinating their unit during missions. Outside of the game, he maintains a personal relationship with Miho Yamanaka.

In personality, Muroya embodies the confident and calculating demeanor of a veteran. He is accustomed to the high-stakes combat and the tactical demands of the missions, approaching challenges with the composure of someone who has repeatedly faced death and emerged victorious. His background as a four-time survivor informs his role in the story, as the Osaka team collectively represents the peak of what a Gantz player can achieve through accumulated points and experience.

Despite his formidable skill and leadership, Muroya meets his end during the climactic battle against the immensely powerful Tengu Alien. His demise serves as a stark reminder that the Gantz world offers no guarantees, even for the most experienced. In his final moments, Muroya refuses to surrender without a fight. He manages to fire an X-gun and lands a debilitating blow on the Tengu, blowing part of its head off. This last act defines his character development, transforming him from a purely pragmatic veteran into a figure of tenacity who fights to the very end. His notable abilities include strategic leadership, extensive combat experience across multiple campaigns, and proficiency with advanced Gantz weaponry.