Emi Sakura
In 2006, when Riho was only nine years old and still in elementary school, she and her older sister Seina began training professional wrestling under Emi Sakura at her Ice Ribbon dojo. She made her debut in an exhibition match against Nanae Takahashi on May 29, 2006 in Shinagawa, Tokyo. On July 25, Riho made her debut for Ice Ribbon at the promotion's third ever event, defeating Makoto. Riho's first year in professional wrestling consisted mainly of matches with Emi Sakura, Hikari Minami and Seina. In March 2008, Riho and Seina faced each other in a four match series, which Riho won 3–1.