Saitama Wild Knights youngster Kenji Sato will make his first Test start for Japan against back-to-back world champions South Africa at London’s Wembley Stadium on Saturday. Sato, 22, won just his fifth cap for the Brave Blossoms in the narrow defeat to the Wallabies in Tokyo after coming off the bench in all four of his country’s Pacific Nations Cup (PNC) games.  Japan’s first-choice hooker Mamoru Harada, who was initially announced as a co-captain for the PNC campaign along