Benjamín, originally named Hikaru Yoshikawa in the Japanese version, is a 10-year-old boy who relocated to Genoa, Italy, as an international student. Encouraged by his diplomat father's passion for football, he joined the prestigious Sanpodestà Junior youth team. Following his parents' death in a plane accident, his aunt planned his return to Japan. Former English football star Albert Robson recognized his potential and adopted him, enabling Benjamín to stay in Italy and pursue football.

He displays exceptional kindness and resilience, frequently showing heroic traits like rescuing a child from danger or comforting strangers without expecting anything in return. Despite facing initial skepticism from teammates and opponents due to his Japanese heritage, he remains determined and optimistic. His unwavering dedication to football fuels rigorous training, often late into the night. His deep empathy prevents him from holding grudges against those who mistreat him, including his initial rival Julian Ray. Instead, he focuses on unifying his teammates, transforming the weak Columbus team into a cohesive unit.

His football journey starts at Sanpodestà Junior, where he struggles as a substitute. Joining the underdog team Columbus, he emerges as their ace player. Under Robson's mentorship and training from Anna Liegi, a veterinary assistant and skilled footballer, he hones his skills, developing the powerful "Aquila Shot" finishing move crucial to his team's strategies. Though Columbus loses the Genoa Cup final to Julian's team, Benjamín's leadership earns him a spot on Genoa's representative team for the Italian Youth Soccer Tournament. Later, he forms the multinational team Jupiter Wings, recruiting former rivals Julian Ray and Cesare Gatti to compete in international tournaments like the European Tournament and Junior Champions Cup.

Relationships are central to his development. He views Robson and Anna as family, sharing a particularly close bond with Robson as a surrogate father. His romantic interest begins with innocent affection for Catherine Ray, Julian's younger sister and a ballet student. He keeps their relationship secret with Anna's help. Even after Catherine moves to Paris for her ballet career, he remains devoted. His ability to inspire extends to teammates like Roberto Concini, the former Columbus captain who cedes leadership to him and becomes a loyal supporter.

International adaptations significantly alter his background. The French dub renames him Benjamin LeFranc and changes his nationality to French. The Italian version calls him Carlos and shifts his origin to Brazilian. In the Arabic dub, titled *Captain Rabeh*, he is reimagined as Moroccan, with his character based on Algerian football legend Rabeh Madjer, adjusting dialogue and cultural references. These adaptations consistently modify his name and nationality while retaining his core traits of determination and leadership.