Makoto Majima is the central protagonist of the Ikebukuro West Gate Park series, a young man in his early twenties who lives in the Ikebukuro district of Tokyo and works part-time at his mother's fruit shop, Majima Fruits. He is well known in the neighborhood as the troubleshooter of Ikebukuro, a reputation he gains for his ability to resolve conflicts, investigate mysteries, and mediate between the area's various gangs, police, and residents. Despite his background as a former top delinquent in high school, Makoto possesses a strong sense of justice and a natural curiosity that drives him to help others, even when he complains that situations are bothersome. He is charismatic, friendly, and kind, and although he is a capable fighter, he prefers to avoid violence and seeks non-violent resolutions to disputes.

Makoto's motivations are rooted in a genuine desire to maintain peace in Ikebukuro and to protect the people he cares about. He refuses to join any specific gang, including the G-Boys led by his childhood friend Takashi, choosing instead to remain neutral and independent. This neutrality allows him to move freely between different factions and earn the trust of both gang members and law enforcement. His role in the story is that of a mediator and investigator, often called upon to solve difficult problems that the police or gangs cannot handle on their own. He evolves from a directionless young man who spends his nights hanging out in West Gate Park with his friend Masa into a respected pillar of the community, taking on cases that range from tracking down serial criminals to resolving personal disputes among friends.

Key relationships define Makoto's life. He shares a deep, long-standing bond with Takashi, the leader of the G-Boys, and they trust each other despite sometimes being at odds. His mother, Ritsuko Majima, is a strong and caring presence who runs the family fruit shop and often nags him about his lack of a real job while simultaneously relying on him for help. He is close friends with Masa and Shun, who frequently accompany him on his various missions. Makoto also maintains a complex working relationship with police officers such as Detective Yokoyama, who both uses and protects him. His personal growth is marked by his increasing involvement in the community, his exposure to new hobbies like classical music and reading, and his development into a columnist for a fashion magazine. Over time, he moves from a reluctant participant in trouble to a proactive force for good in Ikebukuro. His notable abilities include sharp investigative instincts, a talent for de-escalating tense situations, physical fighting skill when necessary, and a vast network of contacts that allows him to gather information quickly.