from wikipedia
Japan and the V sign in photographs
One account of the V sign's use in portrait photographs claims that during
the 1972 Winter Olympics in Sapporo, Hokkaidō American 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.[27] According to another theory,
the V sign was popularized by the actor and singer Jun Inoue, who showed it
in a Konica photo camera commercial in 1972.