Reiya Amuro is the head coach of the golf team at Raijin Girls’ Academy. A former professional golfer who's pro career was cut short, Reiya manages the golf team and acts as Aoi's mentor as she progresses in her own pro career. He also brings Eve onto the team and teaches her to a degree.
In Season 2, it is revealed that Reiya is more than just Aoi's coach, he is also her biological father. In his last game as a professional golfer, where Reiya was playing for the right to marry his lover, fellow golfer Seira, a sudden physical illness forced him to drop out of the competition, causing him to lose both the tournament and Seira's hand to Kazuhiko Amawashi. Yet beforehand, he managed to get Seira pregnant with his kid, who would be Aoi. Kazuhiko found out about Reiya and Seira's kid, and agreed to raise Aoi as his own daughter, keeping the affair secret from the public. After hiding the truth from Aoi for fifteen years, Reiya eventually would confirm Aoi's suspicions that he was her real father.
