Hara made his professional debut in 2010, and won the All-Japan Minimumweight Rookie Tournament in November.
[1] After three successful defenses, Hara defeated Donny Mabao for the vacant OPBF minimumweight title on March 30, 2014, in Fuji by majority decision.
Instead of waiting for a world title match, Hara make the risky decision to defend his OPBF belt against up-and-coming fighter Kosei Tanaka on October 30, 2014, in Tokyo.
[3] After an easy second-round knockout against Thai fighter Petchnamchai Sor Sakulwong, Hara was given a shot at the IBF World minimumweight champion, Katsunari Takayama, on September 27, 2015.
During the fight, Takayama suffered a cut above his left eye in round three, but eventually overwhelmed Hara with power shots to the body and head.