Here's what Wikipedia says... apparently it must originate from Japan.
Japan and the V sign in Photographs
During the 1972 Winter Olympics in Sapporo, figure skater Janet Lynn stumbled into Japanese pop culture when she fell during a free-skate period—but continued to smile even as she sat on the ice. Though she placed only third in the actual competition, her cheerful diligence and indefatigability resonated with many Japanese viewers, making her an overnight celebrity in Japan. Afterwards, Lynn (a peace activist) was repeatedly seen flashing the V sign in the Japanese media. Though the V sign was known of in Japan prior to Lynn's use of it there (from the post-WWII Allied occupation of Japan), she is credited by some Japanese for having popularized its use in amateur photographs.[23] According to the other theory (actually present in the Japanese version of this entry), the V sign was popularized by the actor and singer Jun Inoue, who showed it in the Conica photo camera commercial in 1972.
Through the 1970s and 1980s in Japan, the V sign was often accompanied by a vocalization: "piisu!" This gairaigo exclamation, which stood for "peace", has since fallen into disuse, though the V sign itself remains steadfastly popular. It is especially popular in photography, as it is a favorite pose of both teens and adults - in Japan and elsewhere in Asia.[citation needed]
Another possible explanation for the popularity (and perhaps emergence) of the sign in Japan is that people (usually children) are asked to answer the question Ichi tasu ichi wa?ni ("two"). Being a Japanese equivalent of saying Cheese, the ee sound makes the photographed ones appear as smiling on the photos. Thus, besides saying "two", they are also giving the answer using two fingers. (meaning "One plus one equals?") whose answer is
The V sign is also commonly used in anime and Japanese live-action shows.[citation needed]/vɯi/ or /bɯi/), an approximation of the English pronunciation "vee" which differentiates it from "bii", the Japanese name of the letter B (as many Japanese speakers hear the voiced labiodental fricative as being the same as the voiced bilabial plosive, see Engrish). A more common phrase is "kachi" which means victory (V for Victory) or luck. Several anime characters incorporate the V sign into their poses, including Ash Ketchum of Pokémon fame, both Sailor Moon and Sailor V, as well as video game characters such as Mario, Sonic the Hedgehog, Chun-Li, and Ling Xiaoyu from the Tekken series.[citation needed] When characters show this sign, it is often accompanied by an exclamation of "Vui!" (pronounced
Due to Japanese cultural influences in the region[citation needed], the V sign in photographs has become popular with young people throughout East Asia and Southeast Asia.[citation needed]
In the Philippines, the popularity of the use of the "V" sign in photographs is mostly done as a mockery of its popularity and usage by their Asian neighbors (in particular, of characters in soap operas having their pictures taken). The "V" sign usually stands for "peace" in the Filipino context and is thus a cause for bewilderment and amusement when seen on Asian commercials, soap operas, and other media. When a person uses the "V" sign in the same manner as it is used in photographs by other Asian countries, it is mostly an attempt to be cute or funny in the photograph. When putting the "V" sign on top a person's head, it usually is done to comically "demonize" that person rather than just give that person Bunny ears.[citation needed]
So... I'm not sure that REALLY answers the question, seeing as though there are multiple reasons. I guess it's as customary as saying "Cheese" is here.
