j leagueLearn about the history, structure, and achievements of the J1 League, the hhest level of the Japanese football league system. The league features 20 clubs, operates on a system of promotion and relegation, and is one ofLearn about the history, structure, and achievements of the J1 League, the hhest level of the Japanese football league system. The league features 20 clubs, operates on a system of promotion and relegation, and is one of