Less than one week after Hitomi Akano announced her retirement from MMA, another former Smackgirl champ has also called it a career. Hiroko “Cat’s Eye” Yamanaka, who captured the Smackgirl open-weight title in 2007, confirmed her retirement this morning after seven years in the sport.

Yamanaka began contemplating her retirement following a January decision loss to Ediane Gomes at Invicta FC 4 that resulted in a concussion. Like her former rival Akano, Yamanaka also took time to consider her next move before ultimately deciding to step away from MMA as an active competitor.

Yamanaka (12-3-0, 1 ND) began her MMA career as an amateur fighter on May 14, 2006. She turned pro six months later and won her first three fights. Despite having a limited skill set at the time, the one-time dominatrix was able to overwhelm her MMA opponents with her size and strength. At 5’11” tall, and fighting at weights nearing 170 pounds, Yamanaka towered over the competition. In her fourth pro fight on September 6, 2007, she defeated Japanese MMA pioneer Yoko Takahashi to become the Smackgirl Open-Weight Champion.

At Smackgirl’s final event in April 2008, Yamanaka suffered her first defeat when she was submitted by the much smaller Akano in the second round of their open-weight bout. Following the loss, Yamanaka signed on with Smackgirl’s successor, Jewels, and she went on to win her next eight straight fights including four inside the distance. Along the way, Yamanaka joined the Master Japan team and made significant improvements to all aspects of her MMA game. She also began cutting weight for the first time and avenged her loss to Akano in a featherweight rematch at Jewels: “Seventh Ring.”

Yamanaka’s lengthy winning streak attracted the attention of Zuffa officials, who had taken over the Strikeforce promotion where champ Cristiane “Cyborg” Justino reigned atop the women’s featherweight division. Whereas some fighters had outright refused to fight Justino, Yamanaka campaigned for a bout with “Cyborg” for many months until she was finally granted her wish on December 17, 2011.

The title fight with Justino did not play out as Yamanaka had hoped, and she was stopped by a barrage of punches in just 16 seconds. However, the result was later overturned to a No Decision after Justino tested positive for a banned steroid metabolite. Yamanaka fought once more for Strikeforce, but she came up short on the scorecards in her fight against Muay Thai sensation Germaine de Randamie.

Yamanaka’s final fight came on January 5th when she made her Invicta FC debut against Gomes in a featured featherweight bout. Yamanaka had her moments in the fight, but Gomes landed some hard shots on the feet and the Brazilian walked away with a Unanimous Decision victory. Yamanaka was taken to a nearby hospital and diagnosed with a concussion. After she returned to Japan, Yamanaka hinted at a possible retirement, though no official decision was made until this past week.

According to a post on her official blog this morning, Yamanaka made the decision to retire on the same day as Akano did, July 31st. She expressed her thanks to those who supported her during her seven-year career and asked that fans continue to support her former teammates at Master Japan.

Though she was unable to capture a championship outside of Japan, Yamanaka rose to become her country’s top female fighterweight in a short period of time and she remains one of the most successful Japanese female mixed martial artists of the past five years.

(Photo Credit: Esther Lin, AllElbows.com / InvictaFC.com)