For thousands of Irish fans at today's match in Yokohama, a win for the Republic and a place in the next round will be thrilling but agonising. Many fans head back to Ireland tomorrow and Thursday, unable to follow the team to Korea because of waiting jobs and dwindling finances.
Dublin fans Peter Whearity and Mark Coughlan are still thinking about travelling to South Korea for the next matches, but Frank Walsh-Kemiss has definitely ruled it out.
"My mother even sent me an e-mail saying: 'If I don't see you by the end of the week I'll take it you're in Seoul,' " says Frank. "But I just can't stay on because of work commitments."
Cost is also a factor. "Some people were saying that it would be cheaper to fly home and go out to Korea than to change their tickets here in Japan and fly over directly," says Frank McCarthy from Ballintemple, Cork.
The Irish fans have taken well to Japan. While many admit to still being scared off by the revolving sushi bars, the hospitality shown by the locals has been one of the most positive aspects for the fans.
"It's something else. The people make it. If you ask where some place is they end up bringing you," says Tim Healy, from the Lough Cork.
Peter Devine from Bishopstown, Cork, says that after the Germany match, when he and his friend entered a Japanese bar, they were clapped "as if we were the team". "They were shouting 'Robbie Keane, Robbie Keane' and ended up buying us drinks."
The Irish fans are certainly among the most visible fans around Tokyo, with green shirts on every corner in the major districts of Shinjuku and Ikebukuro.
Robert Barry, from Bishopstown, has been getting the celebrity treatment because of his red hair.
"A lot of the Japanese dye their hair red so when they see the real thing they are really interested. Schoolgirls wave at me on the train. It's great."
Perhaps even more fans would have come were it not for misleading information about the cost of food and drink in Japan. "It's not as expensive as it was made out to be and a lot of people stayed away as a result," says John Devereux, from Rosslare Harbour.
"You can pick up a pint bottle of Asahi beer in a Japanese bar for about 400 yen (about €6) and get a meal for about the same," he adds.
"You have to shop around for food and drink. If you drink in an Irish bar all night, yes, it will be expensive," says Billy Love, from Carriglowe.
Irish fans living in Japan may be somewhat relieved if the team qualifies for the next round and heads to Korea.
Engineers on work experience and English language teachers have their floors full with friends and relatives from home. One fan said he had nine people staying in his one-bedroom apartment.
But for the moment all attention is on today's match, as the green-clad fans head down by train to Yokohama singing the Fields of Athenry next to Japanese workers going about their business.