If you loved Hans Christian Andersen's The Little Mermaid, try The Little Prince and the Eight-Headed Dragon
A bridge between a film you've already seen and one most people haven't. The Little Prince and the Eight-Headed Dragon has roughly 3.6× fewer votes than Hans Christian Andersen's The Little Mermaid — it's a deeper cut, not a mainstream recommendation. Here's what they share, and what the second one does that the first one doesn't.

Hans Christian Andersen's The Little Mermaid

The Little Prince and the Eight-Headed Dragon
What they share
Theyboth carry the tender mood tag, and they sit in Animation / Family / Fantasy territory. If that's the register that drew you to Hans Christian Andersen's The Little Mermaid, the second film will land in a comparable space — through a different lens.
What The Little Prince and the Eight-Headed Dragon is
Apparently someone decided kids needed more dragons. Susano embarks on a journey to find his siblings after his mother's passing. It's a family affair with fantasy creatures.