Carolina Marín
In February, Yamaguchi represented Japan at the Asia Mixed Team Championships held in Ho Chi Minh City, Vietnam, and helped the team win its first mixed team championship. In the same month, she won the women's singles title at the German Open. In March, she played in the India Open, losing to the top seed and Olympic champion Carolina Marín in the semifinals. In April, she participated in the Asian Championships held in Wuhan, China, losing to Tai Tzu-ying in the final.