The Saitama Prefectural Police department on Monday filed charges against three Urawa Reds supporters for violating the Road Traffic Act before and after the December 9 final of the 2018 Emperor's Cup.
Fans of the J. League first division side gathered before the match at the road entrance to Saitama Stadium, setting off road flares as well as fireworks as the Urawa team bus arrived.
The same group of fans again used pyrotechnics after the match, which Urawa won 1-0 over Vegalta Sendai.
According to the police department, it is the first time that such charges have been filed in relation to the use of flares at a sporting event in Japan.
In February, the Japan Football Association handed Urawa a ¥2 million ($18,000) fine for several fan-related incidents at the Emperor's Cup final, including the use of flares as well as an unsanctioned choreography display hung across the main and back stands by Reds supporters.