Kojirō Saeki (佐伯虎次郎, Saeki Kojirō) looks really laid-back and gentle, but looks can be deceiving, for he really is a very dangerous player. His talent for tennis is natural, and is accompanied by his above-average sight, which makes him even more difficult to beat. Saeki is also Rokkaku's Vice-Captain, and like Aoi Kentaro, seemed to be randomly selected by their coach. He was also the childhood friend of Shūsuke Fuji, and is still good friends with him.