Ireland fans turned Niigata green today as they set about celebrating their draw with Cameroon.
The supporters posed for photographs with locals, who seemed stunned by the hordes brightly dressed in green.
The crowd was good-natured before and after the game, with Irish supporters cheering the arrival of Cameroon fans.
Hundreds were taken from the stadium by bus into the city centre, where dozens of Japanese police lined routes to the station, and described the atmosphere as "electric".
Scores more had watched the game from local bars, where they mingled with Japanese, English and Mexican fans.
Most seemed satisfied with the 1-1 draw, but said their team were unlucky not to win.
Mr Neil O'Connell (33) from Shannon, Co Clare, said: "We had a poor first half but it got better in the second. It took the players a while to warm up, and the crowd as well.
"They were pulling together, perhaps they were a bit nervous in the first half."
Other fans agreed that the team was working well together.
Mr Michael Bell, from Belfast, said: "They played together. We were unlucky not to score more in the second half. It was an electric atmosphere. I do not think the Japanese knew what hit them.
"The fans stuck together as much as the team did."
Mr Brendan Nugent (31) from Dublin, said: "I think the support got them going. The crowd got well behind them in the second half."
Roy Keane's absence was not a worry for many fans, who said they thought the squad had put in a great performance.
As fans waited for the kick-off some aired their ill-feeling towards the disgraced captain by chanting: "Are you watching Roy Keane?"
Pierce Rowe (46) from Dublin, said: "They've showed him today they can perform well without him, and they showed us a united front.
"The general feeling from the Irish is that Roy Keane has let us all down."
PA