In his debut Ao defeated fellow Japanese boxer Hiroshi Kashihara with a second round knockout.
Ao is managed by the Teiken Boxing Gym in Tokyo, and trains under Sendai Tanaka's guidance.
[3] After thirteen unbeaten fights, Ao beat Koji Umetsu for the Japanese featherweight title in March 2007.
Despite flooring Larios in the 4th round, Ao managed to lose a decision in the close and contested bout.
[4] On his first defense of the title held on July 14 that same year, Ao lost to Elio Rojas by unanimous decision.