Mizuki Hiruta W10 Kanako Taniyama... Japan's Mizuki Hiruta won the vacant WBO women's 115-pound champions on Thursday at the Korakuen Hall. Hiruta (4-0) scored a seventh-round knockdown en route to defeating Kanako Taniyama (5-2-1) by unanimous decision. At age 26, Hirua was nine years younger than her oponent, but both must be considered as novice boxers.  The title was last held by Tamao Ozawa, who last defended it in May against Miyo Yoshida by split decision. Hiruta tied Japan's record of becoming a world champion in women's boxing in her fourth pro bout. She has star potential.