The V was popularized by Winston Churchill as a victory salute after WWII. In years to follow, it was also used by Charles De Gaulle and Richard Nixon. In the sixties, it was adopted as a sign of peace by hippies protesting the Vietnam war.
In recent years, it has become prevalent in East Asian countries such as Japan, South Korea and China. The use of the V has become a meme associated with Asian people and taking photos. The popularity of the V can be traced back to 1972; although there is no definitive answer as to who was the person to spread craze. The first theory points to a popular Japanese actor and singer named Junji Inoue. He was featured in a Konica commercial taking photos of people all giving the peace sign. According to Inoue, the idea for the sign was based on his perception of it's popularity in the United States. The second account is from the American figure skater Janet Lynn, who was competing in the 1972 Sapporo, Japan Winter Olympics. During her free style performance, she fell on the ice, but smiled through, and went on to win the bronze medal. Her cheerful face made her an overnight sensation with the Japanese. Lynn, a peace activist, was frequently shown in print media and on television flashing the peace sign and has been credited with popularizing it in Japan.
Sources:
Tyler Bell Blog: Origin of the Two Fingered Japanese Victory Salute