SELECT MIN(season) FROM table_name_52 WHERE races = "6" AND series = "all-japan gt championship" AND wins = "2"
Apa musim terkecil dengan 6 balapan, 2 kemenangan, dan serangkaian Kejuaraan GT All-Jepang>
CREATE TABLE table_name_52 (season INTEGER, wins VARCHAR, races VARCHAR, series VARCHAR)