At the age of 20, he became the 500 metres world champion at the 2005 World Single Distance Championships, leaving behind Hiroyasu Shimizu and Jeremy Wotherspoon. After this achievement he was considered to be one of the favourites for achieving a medal at the 2006 Winter Olympics in Turin. Prior to that 500 metre race, he named three skaters as his toughest competition: Jeremy Wotherspoon of Canada, Joey Cheek of the United States, and Dmitry Dorofeyev of Russia. Cheek and Dorofeyev won gold and silver, respectively, while Kato finished in sixth place. He was also beaten by his own countryman, Yūya Oikawa, who was fourth.