Yoake Tsugeru Lu no Uta

Kai Ashimoto, a withdrawn middle schooler, resides in Hinashi Town with his father and grandfather, a parasol maker. After his parents' divorce, he relocated from Tokyo to his father's hometown. Struggling to express his emotions to his family, Kai feels isolated and disheartened about school. He finds solace in writing and uploading songs online. When classmates Kunio and Yuuho invite him to join their band, "SEIREN," he hesitantly agrees and goes with them to Merfolk Island, their practice location. There, they encounter Lu, a mermaid who sings and dances joyfully. As Kai spends time with her, he gradually gains the ability to express his true thoughts.