Hugo, a successful 25-year-old guitarist, returns to his late Grandma Rosemary’s cottage, feeling remorseful for how he treated her. In the humble house, he reflects on his past actions, remembering how he mocked her job as a street sweeper and resented her financial limitations. Despite Rosemary’s efforts, Hugo rejected her gestures and berated her in front of friends.

Upon her death, Hugo inherits an urn with Rosemary’s ashes, initially dismissing it as inconvenient. As he explores her house, he discovers a locket in the urn, prompting him to read her diary. The diary reveals Rosemary’s past, including a deep but unfulfilled love with a childhood friend, Henry. Motivated by newfound empathy, Hugo decides to scatter Rosemary’s ashes in the sea, accompanied by her dog, Sunny.

Hugo embarks on a journey to find Henry, discovering the elderly man’s loneliness and heartbreak. He shares Rosemary’s story, including the unposted letter and love letters from Henry. Together, they scatter Rosemary’s ashes at her favorite beach. Hugo returns to his life, accompanied by Sunny, and writes songs about his grandma’s lost love, finding success and redemption in his music.

In summary, Hugo’s journey of remorse, discovery, and redemption unfolds as he reflects on his treatment of Rosemary, learns about her past, and seeks forgiveness through scattering her ashes and honoring her lost love with Henry.