Tsuyoshi “TK” Kohsaka (高阪 剛 Kōsaka Tsuyoshi, born March 6, 1970) is a Japanese mixed martial artist and professional wrestler who most recently competed in the Heavyweightdivision of RIZIN. A professional competitor in MMA since beginning his career in 1994, he has competed in high-profile promotions, such as the UFC, RINGS, Pancrase, and DEEP. Kohsaka is known for his conditioning and grappling prowess as well as fighting many of the greatest heavyweight and light heavyweight fighters of all time. His “TK guard” position, a precursor to modern butterfly guard, is famous for its efficiency; former UFC champions Frank Shamrock and Maurice Smith have both credited him with having vastly improved their work from that particular position.[1]