Airi Onuma, left, poses for a photo with Tokyo Paralympics wheelchair tennis player Manami Tanaka in Tokyo on Aug.... As a ball girl during the wheelchair tennis competition, Onuma's role is key in ensuring the matches go like clockwork with players getting what they need, whether it be balls, towels or whatever else, quickly and efficiently.... They have one of the most visible jobs in tennis, but they are at their best when they are not noticed....