He is generally very relaxed and in control, often seen with a calm and content expression on his face with his eyes seemingly closed from lightly smiling, and rarely plays at full power. He only seems to do so when he witnesses some form of injustice or wins on the behalf of others who placed their personal health at risk playing tennis. For this reason, data-driven players like Inui and Mizuki cannot predict his movements at all. Fuji later admits to Tezuka that this is due to the fact that he has zero motivation to win, at least prior to the Nationals. There are a few people that can "wake" the true player in Fuji and force him to play seriously, and these few are either nationally ranked or extremely talented tennis players. Seigaku teammates Kunimitsu Tezuka and Ryoma Echizen, Shitenhōji captain Kuranosuke Shiraishi, Hyotei Gakuen Chuto Bu regular Yushi Oshitari and Rikkaidai Fuzoku regular Akaya Kirihara have been acknowledged by Fuji to be actual challenges. When he is excited, provoked, or serious, Fuji reveals his sharp eyes: light brown in the manga and blue in the anime.