Diehard Japanese football fans have been warned to tone down their cheers to avoid trouble when the Blue Samurai clash with bitter rivals North Korea next week in their away World Cup qualifier.
Supporters should refrain from the use of loud speakers and spirited drum beating at the Kim II-Sung Stadium during Tuesday's match in Pyongyang, said Nishitetsu Travel, logistical coordinator for Japan's official tour.
Japanese national flags and banners also will not be welcome "to avoid any potential troubles," the travel agency said.
"We are going to a nation with which Japan has not diplomatic relations. Should something unexpected happen, we will not have the Japanese embassy or a consulate," to help, said Takeshi Kumai, an official with the travel agency.
"We believe the customers understand the situation," he said, also urging fans to refrain from displaying anything with political connotations.
Relations are tense between Japan, which once colonised the Korean peninsula, and North Korea, whose agents in the 1970s and 80s abducted Japanese citizens to help train Pyongyang's spies in Japanese language and customs.
The Japanese expect a tough battle against the North Koreans who will be making an all-out effort to win their home game after a nailbiting 0-1 loss at their previous encounter in September in Saitama, north of Tokyo.
For the upcoming game, North Korea's football authority has set aside a total of 150 seats for Japanese spectators.
The Japan Football Association was given 70 of the tickets, and sold 65 of them for fans through the official tour, which sold out quickly.
North Korea has also allowed 10 Japanese journalists to cover the game, which will be broadcast live for Japanese TV viewers.
The tour will leave Japan on Monday for Pyongyang via Beijing, where participants will give up their mobile phones until they leave North Korea.
The fans will have a sightseeing tour of Pyongyang in Tuesday morning, before the early evening kickoff.
"Travellers will be advised to follow instructions from (North Korean) attendants during their stay," Kumai said.
Japan and North Korea have had tense ties, but have been placed in the same Asian qualifying round Group C along with Uzbekistan and Tajikistan.
The Japanese government will dispatch a team of 13 officials to Pyongyang from Saturday through Wednesday in an effort to minimise the risk of "unforeseen events" for the fans, Foreign Minister Koichiro Gemba told reporters.
The Japanese government urged those going to North Korea to "abide by the various restrictions," Chief Cabinet Secretary Osamu Fujimura said.
Tokyo imposes sanctions on the secretive neighbor in protest at its nuclear weapons programmes and its reluctance to come clean on the fate of Japanese nationals it admitted to kidnapping in the Cold War years.
North Korea has demanded Japan to atone for its harsh colonial rule of the Korean peninsula before and during the World War II, and said its nuclear programmes are for peaceful use.