Tonbo Ooi faced the tragedy of losing her parents in a car accident at a young age. Raised by her grandfather, Gonji Ooi, a fisherman residing on the island of Kagoshima in the Tokara Islands, Tonbo finds solace in the game of golf using her father's treasured No. 3 iron. The island boasts three golf courses, all crafted by the islanders themselves.
The story kicks off when Tonbo crosses paths with Kazuyoshi Igarashi, a former pro golfer who arrives in Kagoshima seeking employment.