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. Many full-time foreign professionals (mainly from Australia and New Zealand) have played in the Top League, notably Tony Brown and George Gregan.
Major Developments and Rule Changes
From the 2008-09 season, three foreign players will be allowed on the field at one time, one more than previously allowed. In addition to the three foreigners, one member of an Asian union, such as South Koreans Kim Kwang Mo (Sanyo Wild Knights) and Choi Ki Joon (Fukuoka Sanix Blues), will be allowed to take the field. From the 2009-10 season one of the three must have played for Japan or be eligible to do so. (). Video referee decisions will be introduced in this season's Microsoft Cup.
From the 2007-08 season a timekeeping system independent of the referee was introduced.
From the 2006-07 season the league was expanded from 12 to 14 teams.