For nearly two decades, Shunji Usui has been a fixture at Urawa Red Diamonds matches at Saitama Stadium in the suburbs of Tokyo, a face in the crowd among the most avid — and sometimes rabid — fans of any Japanese soccer club.

In recent weeks, though, Usui's pride in the former Asian champions has been tempered by embarrassment at seeing the team he loves held up as a symbol of the kind of intolerance critics say has been emboldened by the conservative politics of Prime Minister Shinzo Abe.

On March 8, a banner with "Japanese Only" scrawled on it was hoisted on a stadium gate behind goal one, an area packed with thousands of the club's hard-core fans. Despite complaints from onlookers, it remained in place until the end of the game.