Big Red Sox fan that she is, US Ambassador to Japan Caroline Kennedy took special pleasure Tuesday greeting Sox pitchers Koji Uehara and Junichi Tazawa. ‘‘This is a great event,’’ Kennedy said at a reception in Tokyo. ‘‘Last fall’s victory would not have happened without these two players here tonight.’’ The two relievers, who were indeed instrumental to the Sox victory, are on a tour to share the 2013 World Series trophy with baseball fans in the country. Earlier in the day, the pitchers presented Prime Minister Shinzo Abe with a Red Sox jersey and talked a little baseball with the Japanese leader. Kennedy, the 56-year-old daughter of President John F. Kennedy, arrived in Japan in November. She’s the first woman to serve as US ambassador to Japan. Also attending Tuesday’s reception were Japan’s first major leaguer, Masanori Murakami, former New York Yankees outfielder Hideki Matsui, and Japanese conductor Seiji Ozawa, who became an ardent Sox fan while serving as music director of the Boston Symphony Orchestra.