Lu Over the Wall

Kai, a middle schooler, lives with his father and grandfather in Hinashi Town, a fishing village, where his family makes sun-umbrellas. After his parents divorced, Kai moved from Tokyo to his hometown, where he now struggles to express his complicated feelings towards them and feels disconnected from his school life. Kai finds solace in writing and uploading songs online. When his classmates invite him to join their band, SEIRÈN, he meets Lu, a mermaid girl who attends their practice sessions on Merfolk Island.