Married for several years and living happily with her husband, Shinichi, Aoi has not yet had children. Into this peaceful life suddenly steps Mamoru, her brother-in-law, who has just secured a new job. Mamoru reveals that he's been invited to play golf by his boss, despite having no experience. With this crucial opportunity potentially affecting his professional future, Shinichi asks Aoi to act as Mamoru's coach. Aoi begins giving Mamoru golf lessons the next day. However, driven by a strong sense of responsibility as a coach, the distance between them gradually closes. Their relationship deepens unexpectedly, heading toward unforeseen developments.