Hideaki Tōjō is a supporting character in the Seidou High School baseball team, belonging to the same generation as the protagonist, Sawamura Eijun. A former ace pitcher from the prestigious Matsukawa youth baseball league, Tōjō entered Seidou with the ambition of making the varsity team as a pitcher. However, faced with the deep pitching roster that included talents like Sawamura and the hard-throwing Furuya Satoru, he made the difficult but pragmatic decision to convert into a position player. Primarily taking on the role of a center fielder, this change allowed him to secure a regular spot in the starting lineup.

Tōjō is characterized by a calm, gentle, and diligent personality. Unlike some of his louder and more energetic peers, he presents a quiet and analytical demeanor, which makes him a stabilizing presence within the group of first-year players. He is highly adaptable and mentally resilient, traits that enabled him to successfully overhaul his playing style for the good of the team and his own playing career. Despite this successful transition to the outfield, an underlying ambition to pitch again remains a quiet motivation, fueling his continuous growth as a player.

Within the narrative, Tōjō serves as a reliable and consistent contributor to Seidou. His ability to play solid defense and contribute offensively makes him a valuable asset. One of his key relationships is with Shinji Kanemaru. The two are close friends and came to Seidou together from the same junior high school baseball team, often supporting and being paired with each other. In matches, Tōjō has demonstrated his clutch capability, such as getting a critical single during the intense fall tournament game against Teitou High School, a hit that helped spark a rally for his team. He is noted for his strong throwing arm from the outfield, a remnant of his pitching days, which allows him to make strong, accurate returns to the infield.

Regarding notable abilities, Tōjō is a capable hitter with decent contact skills, though his power is more modest compared to the team's primary sluggers. His true value comes from his versatility and residual pitching knowledge. Although he is an everyday outfielder, he retains the ability to pitch. Even after converting positions, his pitching arsenal includes a curveball, slider, and even a changeup, which he demonstrated when helping Sawamura learn the pitch. This fundamental understanding of pitching also aids him in the outfield, giving him an edge in reading batters and tracking fly balls. He is a well-rounded player whose mental fortitude and selfless attitude make him an important part of Seidou's depth and team chemistry.