In chapter 6 (maybe earlier)As pointed out by TheNextMadKing you get access at chapter 4 from now on you can walk up to the green guy on the counter in the school building, he will give you a side quest named 'a weird place for a match', walk to the right into the second door and talk to the student
the actual match is a kind of rock, paper, scissor. You can choose between throw, catch or focus
What i did, if i had a ball keep picking throw until you hit the opp, if you need a ball pick catch, don't bother with focus
you have to win 3 rounds