If you loved Towa no Quon 1: The Ephemeral Petals, try Devilman - Volume 1: The Birth
A bridge between a film you've already seen and one most people haven't. Here's what they share, and what the second one does that the first one doesn't.
You already loved

Towa no Quon 1: The Ephemeral Petals
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Devilman - Volume 1: The Birth
What they share
Both films are directed by Umanosuke Iida, and they both carry the surreal mood tag, and they sit in Action / Animation / Fantasy territory. If that's the register that drew you to Towa no Quon 1: The Ephemeral Petals, the second film will land in a comparable space — through a different lens.
surreal
What Devilman - Volume 1: The Birth is
Tokyo. Night. Distant sirens. A shy teen merges with a demon to save humanity. The process transforms him into a being of terrible power. One hopes his old friend Ryo knows what he's doing. Worth a look for fans of 80s anime horror.