Lu Over the Wall

In the quaint seaside town of Hinashi, 9th grader Kai Ashimoto (足元カイ) trudges through life with a perpetual cloud of pessimism hovering above him. His days are filled with the quiet rhythms of his grandfather's umbrella-making workshop and the occasional jam sessions with his friends Kunio (国夫) and Yūho (遊歩), who share his passion for music under the moniker "SEIRÈN". The trio's camaraderie is their anchor in a world that often seems too dark to navigate.

Kai's life takes an unexpected turn when he stumbles upon Merfolk Island (人魚島, Ningyojima) and meets Lu (ルー, Rū), the enchanting ningyo girl. As they bond over their shared love of music, Lu's fish fin transforms into a pair of human legs, setting in motion a chain of events that will forever alter the fabric of Hinashi.

With Lu by his side, Kai learns about her kind: gentle creatures who can't withstand the harsh rays of sunlight lest they burst into flames. He also discovers the heart-wrenching truth behind Lu's mother's tragic demise at the hands of a careless ship. As their friendship deepens, Kai introduces Lu to Yuho and Kuino, but his selfish nature begins to manifest as he becomes increasingly absorbed in Lu's meteoric rise to fame.

When SEIRÈN plays at an old merfolk-themed amusement park on an island near Hinashi, Lu's star power shines brighter than the sun itself. Her captivating presence mesmerizes the crowd, and Yuho becomes disheartened by her sudden stardom. As tensions simmer beneath the surface, anti-merfolk sentiment begins to simmer in the town, fueled by fear and misunderstanding.

The situation reaches a boiling point when Yūho's father accuses Lu of being responsible for his daughter's disappearance. In a desperate bid to save her from the clutches of the vengeful townspeople, Lu's father unleashes a curse that threatens to engulf Hinashi in a devastating flood. As Kai and Yūho join forces with Lu and her family to undo the damage, the merfolk rally together to reclaim their rightful place in the town.

In the aftermath of the crisis, the people of Hinashi come together to create an extraordinary spectacle: a sea of umbrellas that shield the sea creatures from the sun's wrath. As the curse is lifted, Kai and Lu confess their love for each other, leaving the future bright with promise. Though they part ways, it's clear that their bond will forever be intertwined with the ocean's tides.