Oishi Shuichiro

 Oishi is a third year student at Seishun Academy and the vice-captain of the tennis club. Along with Eiji Kikumaru, he is part of Seigaku's "Golden Pair," a doubles team that made it to Nationals the year before the series takes place. He is very observant and patient baseline player, cited boring by Eiji. Oishi is a very responsible character and cares deeply about the team.