I don't think there should be one. What if only the shirt is visible in the picture, or if it's a gym uniform with shorts instead of buruma?
Posted under General
I thought buruma already did imply gym_uniform, I'm sure it used to. gym_uniform implicating buruma would imply that there is no male gym uniform, and there clearly is, and would discount tracksuit bottoms as Shinjidude says, and also girls wearing a gym top with nothing on their lower half.