'The Song of Lu, the Dawn Announcer') is a 2017 Japanese animated fantasy film produced by Science Saru and released by Toho about the eponymous ningyo.

One day, Kai explores Merfolk Island (人魚島, Ningyojima) and meets Lu (ルー, Rū), the ningyo girl.

When Kai accidentally reveals the secret of the merfolk to the townspeople, Lu's love and power of music makes them dance around town.

Meanwhile, anti-merfolk feelings have been rising in the town, and when Yūho cannot be found by her father, he puts the blame on Lu and captures her.

In the process of helping, the merfolk destroy the natural cliff which shades the bay from the sun, exposing themselves as the dawn breaks.

The website's critics consensus reads, "Lu Over the Wall can be more fun to watch than to follow, but director Masaaki Yuasa's distinctive visual style offers colorful compensation for an occasionally scattered story.

"[19] Metacritic, which uses a weighted average, assigned the film a score of 62 out of 100 based on 14 critics, indicating "generally favorable reviews".

[20] Charles Solomon from Los Angeles Times wrote, "Yuasa's bold imagery and sometimes convoluted storytelling defy the conventions of traditional animated filmmaking, but he is clearly an artist with an individual vision whose work offers something genuinely new and eye-catching.

"[21] On the other hand, Simon Abrams from RogerEbert.com said "Still, I can't lie: I was bored throughout the 112 minutes I spent watching Lu over the Wall.