track ands field running
In 1928 Japan won it's first gold medal. It does vary for Japan's most (gold) medals in that Olympic sport. It could be in the winter or summer olympics. Personally I think they would have more ping pong medals.
Women's Mogul
Men's football was a demonstration sport at the 1896 Games in Athens and became a medal sport at the 1900 Games in Paris. Great Britain won the first gold medal. Women's football became a medal sport at the 1996 Games in Atlanta. The United States won the first gold medal in women's football.
Andy Murray won the gold medal for men at the 2012 London olympics. Although he is from Scotland his medal counted toward the Great Britain total-- a first gold medal in this sport!
That was basque pelota at the 1900 Games in Paris.
Jack Beatson
Badminton is the official sport of Indonesia. Indonesia has won a Gold medal since the sport was first introduced in the Olympic Games.
soccer
Well, this Japan' 1st gold medal in Japan's Games, they only got 1 gold medal when, Yukio Kasaya won gold in the ski jumping 70m, though they got 11th in gold medals, no other country more then 10 gold medal
Tug-of-War in 1900
The first Asian to win a gold medal in Olympic Athletic competition was Mikio Oda of Japan who won the triple jump competition in the 1928 Summer Olympics in Amsterdam.
Volleyball debuted at the 1964 Summer Games in Tokyo. The Soviet Union won the men's gold medal and Japan won the women's gold medal.