Yoake Tsugeru Lu no Uta

These movies share a similar plot in a sense of boy meets mermaid and magical endeavors ensue. Ponyo and Lu over the wall are two very differently stylized movies respectively. If you enjoyed Ponyo and want to see a different approach to boy meets mermaid with added musical elements I would recommend Lu over the wall. 

Both were directed by Masaaki Yuasa and are visually similar. Music, the ocean, and characters with magical water-related abilities play a central role in helping the protagonist find closure. 

Change happens. For children, change isn't always a positive thing even though the adults around them may think it as such, and they must find their own way of coming to terms. In these stories, the main protagonist is having to deal with a change that involves family and finds themselves drawn into a mysterious psychedelic world as a form of escape, yet - this world, it isn't something they simply imagined up to escape from that change they wanted to escape from. 

Both Tsuritama and Lu no Uta take place in a fishing village and have a group of kids befriending a supernatural being. Without spoiling anything, let me just say that these two have basically the same setting and have a lot of similar elements, including villagers helping the main group, local legends, and, of course, lots and lots of seawater and fish. Both anime are extremely colorful and beautifully directed. In my opinion, Tsuritama explores the topic of friendship better and its characters are a bit more interesting while Lu no Uta is basically a family movie mostly carried by the directional talent of Masaaki Yuasa. That being said, both anime are absolutely worth watching. I can almost guarantee that if you liked one, you will definitely like the other! read more 

~abstract plot and animation ~Both star a boy and a girl character ~Main female character is main plot point  

Yoake Tsugeru Lu no Uta is essentially The Little Mermaid without the contract with the sea witch, the coming-of-age ceremony to go to the surface, the plot to murder the prince, the tragic ending, or the romance. Ok, Yoake Tsugeru Lu and The Little Mermaid aren't that simular, aside from the fact that their both about a relationship between a mermaid and a human and they take place by the sea. 

Both are movie's whose stories in plot synopsis and set up sound very like a ghibli film, but then have distinctive animation styles that are associated with their respective directors. Amusingly Momo's director is known for his realistic rotoscoped style, while Lu's director is know for his exaggerated colorful style. The main character in both in a gloomy kid who has moved a small seaside town from the city and then has an experience with yokai.  

- Both are movies that share a lot of song and creatures that come from the water - Main male MCs are teens that are trying to figure out what their purpose in life; coming of age - Catchy songs, and colorful animation 

Both anime about young male protagonist investigating the mysterious girl related to sea. 

Wacky animations, imaginative ideas, and a sense of childlike wonder. If any of these things appeal to you, then look no further than these two. They both give off a similar vibe, being directed by Yuasa. They are generally very jolly, with some of the best facial expressions in anime. The music really helps with the atmosphere as well. They both have a good balance of comedy, contemplative moments, and light drama, but nothing too heavy. If you want to watch something that reminds you of a dream-filled childhood, you can't go wrong with either.