Urawa Red Diamonds have protested racist against the online postings targeting their two Brazilian players following the first leg of the AFC Champions League final against Saudi club Al Hilal in Riyadh on 18 November.
After the game ended in a 1-1 draw, photos including racist content were reportedly posted on Instagram disparaging midfielder Rafael Da Silva and defender Mauricio Antonio.
A fan of Al Hilal is believed responsible for the postings, according to Japan media outlet Ashahi.
Da Silva was the player scoring the opening goal of the game in Riyadh.
The incident was also reported to the Asian Football Confederation (AFC) on Wednesday. Meanwhile, the Japanese team also released a statement calling for the eradication of discrimination.