Keiichi Kamizaki belonged to the Eighth clan in Darwin's Game. He had short hair and initially wore the clan uniform: a white sleeveless shirt, black vest displaying the number eight, and jeans. During the Shibuya Treasure Hunt, he suffered facial injuries that left scars and cost him his right eye permanently, leading him to wear an eye patch and switch to darker clothing like shirts, jackets, and pants afterward.

Originally adhering to conventional views on death, Kamizaki experienced profound guilt after accidentally killing his semifinal opponent in a national karate tournament, causing his withdrawal. Wang later influenced him to overcome his discomfort with killing through repeated violence, shifting his philosophy to nihilism. He adopted the belief that humans are destined to die from birth.

His combat skills centered on the Tempest sigil for wind manipulation. As a near-championship level karate practitioner, evidenced by his tournament performance, he remained undefeated in direct combat. During the Sunset Ravens and Inukai's assault on the Eighth clan, he easily overpowered Inukai. His sole defeat came through clan battle mechanics, losing all points without physical defeat.

He used his mother's maiden name "Katsura" as his player alias. His narrative concluded during the clan conflict, with no documented development beyond this point in available sources.