Only the most devoted rugby aficionados believe that the Hong Kong Sevens tournament is actually about the sport. The rest of the city -- and the scores of visitors who descend on the Chinese territory for the weekend -- care about only one thing: the party.

Some 40,000 spectators clad in fancy dress will pack out the Hong Kong Stadium for the three-day annual event, held 23 to 25 March this year. Last year's standouts were Angry Birds impersonators, mostly male tutu-clad "Black Swan" ballet dancers, and troupes of sombrero-sporting Mexicans (since it was the Mexican team's first year in the tournament).

Some attendees come to watch the matches. Others fall in love. Most, though, engage in debauchery that's so notorious some residents purposely flee town to avoid the inebriated hordes that overflow the streets of Central and Wan Chai, turning the city's main arteries into an all-night outdoor after party.

But amid the pitchers of Pimm's and the crazy costumes, there are some touching examples of cross-cultural sporting camaraderie. During the 2011 Sevens, right after the earthquake and tsunami in Japan, that nation's team earned a heartwarming amount of applause, support and respect from the usually rowdy crowd. This year, thanks to benefactors, Laos will field a team for the first time, a 10-man outfit that will travel to Hong Kong on a shoestring budget to compete in a smaller, related tournament. The trip is an effort to showcase the developing country's efforts at promoting healthy recreation and mentoring local youth. Maybe one year soon, we'll see a Laotian team at the Sevens.

Hana R Alberts is the Hong Kong Localite for BBC Travel