Guessing from the exciting score, that's a football/soccer. Checking...yep.
Only 150 tickets were allocated to Japanese supporters, and players were held up for four hours at immigration.
They were told off for laughing and had items such as bananas, chewing gum and instant noodles confiscated, Japanese media said.
That list of dangerous contraband sounds like wise advice on what to bring to Best Korea. I suspect the J-supporters bought bananas, chewing gum and instant noodles as gifts/bribes as well as for their own needs.
Best Korea doesn't have fruit when it's not in season (bananas would be rare there); chewing gum is useful to equalize pressure on the plane flight (and would be a great gift to the local children); and instant noodles are a good backup in case they want to avoid a meal* (typically Japanese travelers put cup-ramen and pre-cooked Japanese rice in a retort bags into their suitcases as comfort food during any trip to alien worlds).
*Maybe the Japanese supporters saw Anthony Bourdain's episode on Korea or Andrew Zimmern's Bizarre Foods South Korea?