Kazuyoshi Igarashi is a former professional golfer whose life was derailed by a gambling scandal. He arrives on the remote Tokara Islands as a man stripped of his career, his family, and his sense of purpose. His journey throughout the story is one of reluctant redemption, as a chance encounter with a young girl forces him to confront his past mistakes and rediscover the joy of the sport he lost.

Before his fall, Igarashi was a skilled and established professional. However, his career came to an abrupt end after he became entangled in illegal betting. While the specific details vary slightly, the core incident involved him accepting a large sum of money—either as part of a high-stakes game with gangsters or as a questionable payment from a younger player. He hesitated to return the funds, and when the golf association discovered the impropriety, he was stripped of his professional qualification. The consequences were devastating and immediate. His wife divorced him, and his relationship with his son fractured beyond repair after Igarashi failed to support the boy’s own interest in golf, instead responding with harsh and dismissive words.

Unable to find stable work and carrying the weight of profound shame, Igarashi responds to a job listing for a development center on Hinoshima, a small island in the Tokara archipelago. He moves there even before his interview is confirmed, seeking a complete escape from his previous life. On the island, he initially presents as a logical, careful, and somewhat cynical man. He is blunt and struggles with interpersonal relationships, a trait that contributed to the breakdown with his own son. He also harbors a specific reluctance to teach amateur golfers, a job he sees as beneath his former professional status.

His role in the story is cemented when he meets Tonbo Oi, a mischievous and free-spirited middle schooler who plays golf with only a worn-down three-iron club. Despite his reluctance, Igarashi is immediately impressed and surprised by her unorthodox, powerful, and incredibly talented playing style, which she developed on the island's single, rustic course. He becomes her mentor, taking on the nickname Igaiga. In this role, he finds a new sense of purpose. Though he once avoided teaching, he proves to be a sharp, analytical instructor with a natural talent for explaining complex techniques and strategies in a logical way. He is determined to hone Tonbo’s raw talent and help her succeed in organized tournaments, seeing in her a potential he believes is worth fostering.

The relationship with Tonbo is the catalyst for his development. Initially uneasy and emotionally empty, coaching her offers Igarashi a second chance to be a father figure and a positive influence, a role he previously failed in. Through her, he begins to let go of his rigid expectations and rediscovers the fundamental fun of golf, gradually accepting that perspective, not location, is what matters. While his past continues to loom over him, his motivations shift from simple escape to a genuine desire to guide a young talent, confronting his own failures in an effort to ensure Tonbo does not make the same mistakes. His notable abilities lie not just in his own residual golf skill but in his profound capacity for logical analysis and his newfound ability to communicate that knowledge effectively to a student with a completely unique approach to the game.