The emergence of the JGTC (All Japanese Grand Touring Championship) in the mid-to-late 1990's saw huge growth within the series, and full factory efforts akin to DTM. The Japanese 'Big 3' (Nissan, Toyota and Honda) all had major factory backed teams such as Impul, Mugen/Dome, Team Tom's and Team Kunimitsu. The major factory backed Nismo R34 GT-R, sponsored by American motor oil brand Pennzoil, became dominant in their 1998 campaign especially. With 2 wins and no finish worse than tenth, drivers Erik Comas & Masami Kageyama win the driver's and constructor's titles with a 17-point lead to Nakajima Racing's Tom Coronel and Koji Yamanishi.
Enter 1999, and Erik Comas one again gets the driver's title by four points from the Castrol Tom's duo of Takuya Kurosawa and Masanori Sekiya. However, with the Nissan's success over two years, there was one round that didn't count for the championship, accepted GT500 cars, but the Nissan GT5000s never raced at yet: the Suzuka 1000km.