Chisako Satoya, a writer, and her father, Kozo, had a long-standing feud and had been living apart for a long time. However now that Kozo, who lives alone, has dementia, she returns to her hometown to begin taking care of him.
In a coastal town attracting artists, 14-year-old Sosuke and his friends stay busy painting and helping with school projects. As carefree children interact with secret-laden adults, the sunlit ocean reflects their contrasting struggles—kids embracing challenges while adults seek elusive answers.