In the anime "Demon Slayer," the sunflower seeds are a symbol of hope and resilience. The main character, Tanjiro Kamado, carries sunflower seeds with him as a reminder of his family and their unwavering support. The seeds serve as a source of strength for Tanjiro during challenging times and represent his determination to protect his loved ones. Additionally, the sunflower seeds also serve as a connection to his sister, Nezuko, as they share a special bond through their shared memories of their family. Overall, the sunflower seeds represent hope, familial love, and the will to overcome adversity in "Demon Slayer."