Kenji Fujima is a third-year student at Shoyo High School, where he serves as both the team captain and head coach, a unique dual role that makes him the only student coach featured in the story. Standing 178 centimeters tall and weighing 66 kilograms, he plays as a point guard and wears the number 4 jersey. Fujima is widely recognized as one of the two best players in the Kanagawa region, forming the legendary pair known as the prefecture's top guards alongside his rival, Shinichi Maki of Kainan. His path to prominence was remarkably early, as he was the first player in Shoyo's history to become a starter during his first year of high school, immediately becoming the team's ace.

Fujima possesses a calm and intellectual demeanor, with a character that shifts distinctly depending on his role. When seated on the bench serving as a coach, he is described as cool, self-controlled, and strategic, carefully analyzing the flow of the game and making calculated decisions. In this capacity, he is respected for his leadership and ability to read opposing teams' weaknesses, motivating his players effectively during timeouts to rally their spirits. However, once he removes his coach's jacket and steps onto the court as a player, his personality transforms dramatically. He becomes an energetic, passionate, and aggressive competitor, described as being "far from rational" once the game begins. This contrast between his composed coaching persona and his fiery playing style is a defining feature of his character, and the entire Shoyo team is known to play at a different, higher level the moment he enters the game.

As an athlete, Fujima is an exceptionally well-rounded point guard with outstanding technical skills, stamina, and mental strength. Being left-handed gives him a natural advantage that opponents often find difficult to counter. His playing style is marked by perfect technique, strong offensive power, and a high basketball IQ that allows him to orchestrate plays that maximize the individual strengths of each of his teammates. While his scoring ability is formidable, he shines brightest by integrating the entire team into the offense, extracting the maximum possible performance from every player on the floor. An often-overlooked aspect of his athleticism is a brief display of baseball talent; he once effortlessly caught a fly ball without a glove and threw a sharp, precise curveball, suggesting he could have excelled in that sport as well.

Fujima's central role in the story is defined by his rivalry with Maki and his team's fateful encounter with Shohoku. He is a proven leader who led his team to the national tournament for two consecutive years, driven by the ultimate goal of winning a championship and finally defeating his rival from Kainan. Prior to his third year, he led Shoyo against powerhouse Toyotama Academy in the Inter-High Championship, where he was intentionally injured by Tsuyoshi Minami, the player known as the "Ace Killer." This injury forced him out of the game and led to Shoyo's defeat, a loss that stuck with him. His final high school summer tournament culminates in a tense match against Shohoku, where he is forced to enter the game earlier than planned as the underdog team begins to close the gap. Despite displaying remarkable skills that astonish the audience, he and his team ultimately lose by a single point. Following this devastating defeat, Fujima does not give up on basketball, declaring his intention to continue playing in the upcoming winter selection tournament. He later watches the finals between Kainan and Ryonan from the stands, visibly driven by a sense of rivalry, muttering that the two teams are fighting for the title of best in the prefecture while he is not even on the court. His story is marked by this combination of talent, leadership, and the tragedy of falling just short of his ultimate goals.