Japan Rugby League One, formerly known as the Top League, is a rugby union competition in Japan. It is the highest level of industrial-professional rugby competition in the country. The Japan Rugby Football Union created the competition in 2003, by absorbing the Japan Company Rugby Football Championship. The chief architect of the league was Hiroaki Shukuzawa who strongly felt the urgency of improving Japanese domestic company rugby to a professional level which would allow Japan to compete more convincingly at Rugby World Cups.