While in high school, Yamaguchi won the national badminton competition, competing in the women's singles event. At the 2nd Asian Youth Games held in Nanjing, China in August 2013, where she represented the Fukushima Prefectural Tomioka High School, she won a gold medal in mixed doubles. In October, she represented Japan at the East Asian Games held in Tianjin, China, where she finished third in the women's singles event. After graduating from high school, she joined the Re-Shunkan Pharmaceutical badminton team.