Tai Tzu-ying
In August, Yamaguchi represented Japan in the World Championships in Glasgow, Scotland, where she played in the women's singles event. She was the No. 1 seed and thus had a bye in the first round. She defeated Denmark's Line Kjærsfeldt in the second round, but faced No. 9 seed Chen Yufei in the third round and was defeated 18–21, 19–21. In October, she played in the French Open and lost the women's singles final to the tournament's top seed, Tai Tzu-ying. She played in the China Open, and in the final, she swept the host's Gao Fangjie 21–13, 21–15 to win her first title of the year.