Gurimu Igarashi is a participant in the Blue Lock project, known for his pragmatic and determined personality. He is a seventeen-year-old with a short, slim build, standing 172 centimeters tall, and has a shaved head, thick eyebrows, and wide black eyes. His nickname is Igaguri, which means chestnut burr and refers to his hairstyle. Igarashi comes from a temple family in Aichi Prefecture and is an only child. His primary motivation for joining Blue Lock is not a pure love of football but a desperate need to escape his predetermined future. He made a deal with his father that if he becomes a professional player for the Japanese national team, he will be exempt from inheriting the family temple, a fate he dreads.

His personality is a blend of awkwardness, religious upbringing, and a sometimes lamentable degree of pragmatism. Igarashi is very self-aware of his own lack of skill compared to the other prodigies in Blue Lock. He started the program ranked dead last at 300th, and his self-described weapon was initially just a never-give-up attitude. This awareness fuels a powerful survival instinct; he is willing to use any means necessary to stay in the competition, leading to a reputation for being annoying or underhanded. He craves recognition and is easily deflated by fear and anxiety, but his stubborn refusal to lose keeps him going.

Igarashi's role in the story is that of a persistent underdog and occasional comic relief who defies expectations by surviving far longer than his talent would suggest. He begins on Team Z, the lowest-ranked team, alongside the protagonist Yoichi Isagi. Igarashi forms one of his few close relationships with Isagi, confiding in him about his fears and his family situation. He struggles to make meaningful contributions during the First Selection, but his determination is shown when he uses his face to block a shot from the prodigy Seishiro Nagi. His most significant development is the creation of his unique weapon, the Malicia Style. This is a cunning dribbling technique designed not to score but to draw fouls from opponents. By baiting defenders into contact and then exaggerating the impact, he forces referees to call fouls, earning his team valuable free kicks. He refines this skill to a high level, claiming he can draw a foul one hundred percent of the time when an opponent approaches from his right shoulder. During the Neo Egoist League, he plays as a defensive midfielder for Bastard München, where his Malicia proves effective enough to disrupt top players like Rin Itoshi. Despite his low overall ranking, his unique tactical foul-drawing ability becomes his key contribution to the team.