Ko Iso, (born April 10th, 1987) is a Nihon Ki-in pro. He become pro in 2002, reaching 2-dan in the same year, and 4 dan in 2005. He was promoted from 4 dan to 7-dan on 27 October 2005 when he beat Kono Rin to claim a berth in the Meijin league. At that time, he was the youngest player to have played in a league. 8 dan in 2011. November 3, 2019, 9-dan (Number of wins = 200 wins).
He is also known as Huang Yih Tzuu, and his name is displayed as such on the Nihon Ki-in page.